The Season Four finale was strong overall and definitely seals up this season as a departure from the poorly-paced crappiness of seasons past (especially Season Three). Plenty of information revealed, lots of plot progression, and a healthy-sized dosage of mystery for its own sake. There have been many explanations floating around for why Season Four has been better constructed than before -- the two principal theories being that the writers now have a hard and fast end-date for the show, allowing them to develop a clearer vision for the remaining story, and the fact that the writers' strike this past year forced the writers to pack more information into fewer episodes. Whatever the explanation is, I likes it.
Having the first scene begin exactly where the final scene of Season Three ended was clever, and strongly suggested that we would find out who Jeremy Bentham is (which we do, predictably, in the very last shot of the episode). At first the fact that Kate stopped the car and got out to yell at Jack seemed a tad jarring, but it makes sense. Until that point Kate's attitude toward Jack's suggestion that they go back seemed to be "Oh, you're a crazy drugged-up fool." Now we know that Kate adamantly refuses to go back to the Island and is enraged by the very idea. The final scene, in which Ben teams up with Jack to try to get the Oceanic Six-Plus-One back to the Island indicates that getting everyone together and willing to return will be a project next season.
The flash-forwards were uneven. The Hurley scenes were great, further teasing out the Bentham mystery (via yet another season finale cameo by WAAAAAALT), and the fact that Shere Khan and company are still relentlessly tailing the Oceanic Six and trying to get their filthy paws on the Island. Kate flashbacks/forwards are almost universally dull, and last night's was no exception. We have no idea whether Claire was really just a dream or an actual communication from the Island. The Jack/Ben scene is unclear on this. We don't know whether the Island wants all six/seven of them back, or whether it wants all of them to stay away, and Ben needs to somehow finagle his way back to the Island by getting them back all at once. The fact that Christian took Claire without taking Aaron, coupled with the dream sequence, suggests that the Island, or some force on the Island, doesn't want Aaron there, but we have no idea why.
The Sun flashforward was 100% dumb for reasons I'll get into below.
As for the Island action, we again got to see a lot of Ben, and a lot of Michael Emerson's acting talents. The Ben/Locke odd couple routine was entertaining, particularly where Ben shakes the flowers at him. It was just a very natural moment. Ben's numerous attitude shifts in the episode were all well-done. His casual, matter-of-fact, "Okay, now what?" reaction to being rescued amid a hail of gunfire and the deal that the Others worked out with Kate and Sayid (whose fight with Keamy, by the way, was awesome); his irritability while setting up the Island move as Locke peppers him with questions (in retrospect there's actually a lot going on here -- He's resentful of Locke for taking his place as the Island Prophet, he's full of rage at the idea of going after Whidmore, he's sad about leaving the Island, etc.); his loss of control when he attacks Keamy... In what was one of the episode's best moments, we see his face turn from exertion to anguish as he rotates the mechanism that moves the Island, realizing that he's about to leave the Island forever (though not really, perhaps, based on the final scene).
There were some good smaller moments on the Island involving the ancillary characters, that set up some things that will no doubt be explored in the coming seasons. The scene with Miles and Rose was great, pitting Rose's unflagging and fanatical commitment to etiquette and propriety against Miles' relentless irreverence and indifference. What was great here is that Miles, jerk though he is, once again goes along with things rather than spark open conflict. Rather than challenge Rose, he just says, somewhat sarcastically, "M-may I eat these peanuts?", just as he never seriously challenged Sawyer's assertion of authority over him.
We find out that Charlotte has some prior connection to the Island but we get no further information whatsoever (other than Charlotte's tendency to react incredulously when people reveal to her that they know things about her she's trying to keep secret). We don't get much Dan action, and we still have no idea why the newscast made him cry or who was with him when he was watching it (I have a feeling it will somehow turn out to be Charlotte, but don't quote me on that).
So, on to what I didn't like. The freighter bomb made no sense at all. Why on earth would Keamy go through all the trouble of (1) smuggling a ton of C4 onto the boat, (2) secretly building a bomb out of it, (3) rigging a remote detonator, and (4) programming the remote detonator to go off by monitoring his own heart rate, and then not tell anyone about it? Or, rather, tell only Ben, somehow relying on the fact that Ben will be so concerned with the fates of a bunch of strangers on a boat who have come to the Island with the specific intention of stealing it from him that he'll immediately surrender? Either he's just crazy, which isn't very interesting, or he's just spiteful and doesn't want anyone else to survive if he doesn't. There's just no way he can realistically expect any useful leverage from the bomb. It's a completely illogical set-up for some pretty dumb plot points. To whit:
An uninteresting exploration of Ben's morals. Ben has always talked about how he doesn't kill innocent people, blah blah blah, but then reacts with Cheney-liked indifference when Locke tells him he just made the boat explode. Presumably, we're supposed to think that this is part of Whidmore having "changed the rules" by killing Ben's daughter, though this fails under Ben's own logic. He absolves himself of responsibility for the deaths of Libby and Analucia because Michael actually pulled the trigger, but never gets a straight answer from Keamy as to whether Whidmore told him to kill Alex before going off half-cocked in search of vengeance. So that was dumb.
The exploding freighter was also a unnecessarily dramatic and non-sensical way to kill off Jin and set up the completely bonkers Sun flashforward storyline. We're supposed to believe that Sun, witnessing her husband and the father of her child get exploded on a boat, swears blood vengeance on the two men she holds responsible for his death (her father and Whidmore), returns to Korea, and then executes her vengenace through... lopsided business deals!!! Seriously, what the hell. The Sun rudder has been broken ever since the beginning of Season Three when she killed (!!!) one of the Others and we never heard about it again. Expect some mad Sun crappiness going forward, folks.
Another nitpicky thing: Unless the Island is floating, which it shouldn't be based on the fact that people are able to get to it and from it using a special set of coordinates, there should have been a much more dramatic set of waterworks when it disappeared. A vanishing volcanic Island would create a hole in the ocean from the surface to the ocean floor. The water rushing in to fill the void would create much more of a disturbance than the modest bloop-bloop we saw in the episode. I'm just saying.
There's certainly more to talk about, but that's about what I have to say. And next season, three words: Weekend at Locke's.