I'll take my thought a little further on this, I see it mainly as a 2010 play and one based on the mid-term elections and their immediate aftermath. She will draw lots and lots of fire, but also tremendous numbers of viewers to Fox, so it is a win-win for Fox, every Conservative that can take advantage of all the wrath and effort being wasted on her by the Left, and a great chance for her to recoup her finances after the debacle of having to pay her personal legal costs through endless unfounded ethics complaint proceedings in Alaska (I'm sure the book deal has already helped a lot on that score, but you can never have too much money).
I don't know if she has further personal political ambitions, but I don't see this as a loss for them if she does, since it will let her see whether she can handle that game without investing in it, and ultimately increase her chances if she turns out to be highly successful in the Fox gig. If she decides that's not for her, or her performance lowers her chances (Possible, but who knows), she still stands to help all other Conservatives by drawing fire and having nothing to lose in fighting with the Libs all the way through 2010 and beyond.
Barring some unforeseen problem like losing the power of speech, I see this as a multi-dimensional win for Conservatives.