About the only thing political junkies were able to agree on, after Sarah Palin's bombshell announcement that she is quitting as governor of Alaska, was that anticipation of her memoirs next year just went through the roof.

The fast-emerging view of Republican Party operatives and commentators - including some of those that have championed her national career since before the beginning - was that Palin just shot her political moose, completing one of the most spectacular flameouts in the modern era.

Some of her staunchest supporters argued that her resignation, 18 months before the end of her term, frees her to pursue a 2012 presidential bid, but they appeared to be speaking more out of hope than expectation.

The betting is that, for the small-town mayor from Wasilla - who shook up Alaskan politics and nearly became vice-president of the US, who wowed sections of the national Republican party with her religious certainties, and appalled and amused vast swathes of the rest of the nation with her apparent ignorance - 26 July will not only be her last day in the governor's office, but will also be her last day in any political office.

On all sides, observers were combing through the rambling resignation speech she delivered on Friday by the lake at her home in Wasilla, flanked by her family.

Could she really be about to take to the national political stage? Or the TV studio?

Or did she and her family just want out of the spotlight, which has turned their personal travails into a tabloid soap opera and her political career into a costly legal nightmare?

The reasons in the speech seemed too many to be consistent and were occasionally outright incoherent.

They included the desire to not be a "lame duck" governor after deciding not to run for a second term, through being fed up with "the politics of personal destruction", to a promise to "effect positive change outside government".

Bill Kristol, the conservative columnist who first touted her as a standard-bearer for the evangelical right and who had spent the past week defending her from more sniping by John McCain campaign staffers, was among those mystified.

He conceded the move was "an enormous gamble" if she did harbour ambitions to be a major player.

"Now she can do her book, give speeches, travel the country and the world, campaign for others, meet people, get more educated on the issues - and without being criticised for neglecting her duties in Alaska," he said.

"Everything rests on her talents, and on her performance. She'll be under intense and hostile scrutiny, and she'll have to perform well. All in all, it's going to be a high-wire act. The odds are against her pulling it off. But I wouldn't bet against it."