"It's absolutely bizarre, and I think it eliminates her from serious consideration for the presidency in 2012," he said.

Palin hinted that she had a bigger role in mind, saying she wanted to make a "positive change outside government." But she kept supporters in suspense, promising later Friday on Twitter: "We'll soon attach info on decision to not seek re-election ... this is in Alaska's best interest, my family's happy ... it is good. Stay tuned."

Jerry McBeath, a veteran political science professor at the University of Alaska Fairbanks, called the pending resignation a "smart move," both for Palin and the state.

"Alaska is an isolated stage from which to operate if you want to figure in American national politics. I don't know what she has in mind, some TV show or some national radio show. There are opportunities for her, I'm sure."

"After all, Rush Limbaugh is getting old, and cranky, and the airwaves and the videowaves would benefit form a new present. She certainly is photogenic, and that is her area of experience. So I would say it's a response to opportunity instead of 'getting out before they get you,'" he said.

As for the state, he said Palin's departure will reduce the distractions and return Alaska to normal politics.

Palin said her family weighed heavily in her decision.