If Palin takes a hit to the chicn and is flattened, part of the losing half of the 2008 presidential ticket that barely gets 200 electoral votes, she won’t be a significant force in national politics ever again.
Recent history shows that losing VP candidates don’t do very well at all. Odds are Palin will suffer a similar fate.
She will be huge for GOP fundraising, though, since the base is in love with her and that will probably continue.
If McCain doesn’t win in 2008, Palin will likely never be president.
From what I can find, the only losing VPs ever to go on to the presidency in the entire history of the Republic are John Tyler and FDR.