The last season of 24 was a real trainwreck, a complete mess in almost every sense. The writers' strike delayed the new season a year so this past November we got the TV movie 24: Redemption as a sort of long teaser though it too was so tedious, predictable and unimaginative that I can't even think of unpredictable, imaginative adjectives to toss at it. Rumors had been that the new season would start in Africa but that was cut out when the creators realized that even though nobody really plays by the real-time gimmick, having Jack stuck on a plane for a big chunk of the season wasn't really good TV. (Though just think: Andy Warhol's 24.) So Redemption was supposed to be a bridge between the seasons and a bit of background for the upcoming one but since we had seen the previews and know that Jack isn't repentant then we also know there's no redemption.
I'll have to admit, though, that Season 7 has been a blast, a modern version of a 30s/40s serial that only cares about movement, impossible situations, good & bad guys and a regular-as-clockwork cliffhanger. (I'm still hoping that someday an episode will end with Jack literally dangling from a cliff. Or even better: Jack Bauer vs. Dr. Mabuse.) It's had some nice set pieces, kept the story changing fairly often, came up with decent surprises and made good use of getting away from LA and CTU. Even the by-now-routine discussions about the ethics of torture were somewhat believable this time and not people shouting bumper stickers at each other. Some of the stuff that seemed a bit forced such as the speed that Walker started emulating Jack or the president's unreasonable stick-to-the-policy approach paid off down the line when their B&W ideas got messily gray. (Not too gray - this is still a show where the lead character is a borderline psychopath and multiple felon but is invariably right.) I would never choose this as an example of TV at its best (nothing like, say, Battlestar Galactica or Heroes) and 24 will never be able to top or even match its second season if only because that element of hey-we-can-do-anything surprise can never be repeated.
The overall structure has played into the sense of unpredictability even if it was probably accidental. The opening episodes focused on a stolen device that escalated into a larger threat but it was still not clear how this would fill an entire season. The answer is that it wouldn't. That initial threat went through its various twists 'n' turns before being mostly wrapped up to make way for the next related one (the assault on the White House) and then that's just moved aside for an as-yet unrevealed but clearly much larger story.
Now there's still a lot of "they can't be serious" moments. The entire infrastructure of the United States on a single firewall that a single guy knows the inner workings, a hacker using odds-ends equipment breaking into the FBI network and outwitting everybody there, a pesticide plant that apparently never designed any failsafe mechanisms, Jack's intimate knowledge of D.C. streets. And of course Tony being alive.
But if this stuff really bothers you, you're watching the wrong show. The last season was bad not because it was implausible but because it introduced characters and storylines that went nowhere (my favorite was the people from district that were talked up for a couple of hours, showed up to take over CTU and then simply vanished), plot devices repeated from earlier, characters forced into odd behavior just to move the plot (Curtis being the prime example), and so forth. All we want is just enough effort that some element doesn't create derision and we'll be cool with that.