This season of "24" has been interesting because it is the first time that the writing staff has had the luxury of advanced planning. Nearly everyone involved with the production has been outspoken in their pleasure at the extra time and thought that has gone into the season arc, and it shows on the screen. While there have been some bizarre plot turns here and there, the buzzword for the seventh season has been "consistency".
Consistency, in the sense that there haven't been many episodes that have soared, nor have there been many episodes that have failed. The majority of the season has been a bit above average, which is better than most seasons of the show thus far. The main problem has not been shock for shock's sake, or retreads of the familiar as an antidote to last-minute scripting. Instead, it's been some of the choices along the way.
First, the good elements. It would have been easy to postpone the effects of the bioagent until the end of the season, thus leaving any explanation for Jack's survival to a later date. Instead, Jack begins suffering immediately, and it's clear that he doesn't have long. The short-term solution was a good way to keep Jack in the story for now.
The long-term solution is a bit less elegant. It seems a bit convenient that research just happens to be available for Jack's particular case, and that it would only require bone marrow donation from a living relative. This is obviously going to be the basis for Kim's oft-mentioned return, and sets the stage for a reconciliation between father and daughter. Given that this season is the beginning of Jack's restoration, this is hardly surprising.
Another good thing is the continued philosophical exploration within the context of the season arc. The season began by asking if someone like Jack Bauer was acting appropriately in the defense of his country. The main question was one of tactics; quite often, Jack must act outside of the strict letter of the law to protect the interests in the nation. Much of this season has been designed to demonstrate why someone like Jack, and an organization like CTU, is a necessary evil.
Starkwood, and Jonas Hodges in particular, stands as Jack's moral opposite. They were willing to conduct extra-legal operations on behalf of the United States government, but they have lost sight of who and what they were fighting to preserve. Jonas is Jack without the patriotism and sense of honor. If Jack is the reason why some agents must stand outside the law, Jonas is the reason why the line must be carefully drawn.
If there is one thing that continues to be a problem, it's the decision to make Olivia the acting Chief of Staff. Not only are her qualifications completely lacking, so far as has been revealed, but her various entanglements and reputation compromise her suitability. It does not speak well for President Taylor that she made such an emotional choice, even under such strained circumstances.
It's also unfortunate that the writers further undermined Taylor by forcing her to violate her own pledge, earlier in the season, not to negotiate with terrorists. Of course, that kind of zero tolerance policy is almost impossible to maintain, and whenever it is seriously challenged, it never fails to imply the weakness that the pledge is meant to deny.