I have mixed feelings.
I've seen the first 3 episodes of this season (well, 2.5 right now, watching the third one).
They're definitely entertaining, and I enjoy watching the show.
However, I think they create too much FUD, with all the terrorist stuff. People are already too afraid of terrorists coming to get them that they're willing to sacrifice just about everything for an anti-terrorist placebo. I think that 24 creates more fear that probably isn't a good thing. But that's just an opinion.
Also, we have a "Media" forum for a reason