Mike Bloomberg has said, unequivocally, that he will not run for president this year. But anybody who thinks that puts an end to the speculation about the New York mayor's political prospects should know better.

Vice presidential picks haven't been decided yet. And as they say in New York, it ain't over till it's over.

Bloomberg confirmed Thursday afternoon what he wrote in a column in The New York Times the night before -- that he is not seeking the presidency.

"I am not and will not be a candidate," he said. "I'm going to try to spend my time being the best mayor I can of New York City for the next 672 days and use the bully pulpit of New York."

With that, Bloomberg effectively ended two years of rumors that he would run as an independent in November. But he's still being hounded by questions about whether he'd consider joining another candidate's ticket.

Barack Obama is the first name that trips off the tongue, a by-product of Bloomberg's much-gawked-at breakfast meeting with the Illinois senator at a Manhattan diner back in November. (Obama picked up the billionaire's tab.)

"Nobody is going to ask me to run as vice president," Bloomberg said Thursday, when asked about the possibility of running with Obama.

He used similar language Wednesday when asked to comment about a story in The Washington Post claiming Bloomberg was among readers' top picks for the No. 2 spot on either party's ticket.

"I don't think anybody is going to ask me to be vice president, and I think that I have one of the best jobs in government," he said.

But the "what ifs" continue, because Bloomberg did not categorically rule it out. The New York Daily News carried an article Thursday keeping the idea alive.

The piece, titled "Barack Obama's dream ticket: Mike Bloomberg for vice president," argued that "Bloomberg is uniquely positioned to complement Obama's strengths and compensate for his weaknesses" by giving the ticket "instant economic credibility" and a "deep resume."

"Perish the thought" is the advice of Larry Sabato, director of the University of Virginia Center for Politics.

"Any Democratic candidate has an excellent chance to carry New York state. [Obama] doesn't need Michael Bloomberg," Sabato told FOXNews.com.

He said Bloomberg could have played a role if the general election race was between Hillary Clinton and Mitt Romney, but absent such "polarizing" figures, Bloomberg will remain on the sidelines, even when it comes to running mates.

Though Bloomberg knows all the major presidential candidates, including John McCain, Sabato said there is a "zero percent chance" that McCain will tap him, since Bloomberg's positions could be too liberal and hurt the Arizona senator with conservatives.

As for the Manhattan meeting with Obama, Sabato guessed, "I think it was just pleasantries. They wanted to be seen in each other's company and they were."

The 66-year-old billionaire businessman, who aides had said was prepared to spend $1 billion of his own cash for an independent campaign, wrote in the Times that while he is not running, the race is too important for him to stay out completely.

"And so I have changed my mind in one area," he said. "If a candidate takes an independent, nonpartisan approach -- and embraces practical solutions that challenge party orthodoxy -- I'll join others in helping that candidate win the White House."

Putting his endorsement and resources behind one of the candidates could make a significant difference.

Obama said Thursday he hopes Bloomberg will look at his track record on energy and special interests, and that "I will definitely be reaching out to him."

Bloomberg also has worked closely with Clinton, his home state senator, and has a friendly relationship with McCain.

Asked what it would take for him to endorse a candidate, Bloomberg said Thursday he wants to hear more details from them.

"I find frustrating that they talk in generalities and don't have specific plans," Bloomberg said. "Health care is as good an example as any. What I have not heard from them is concrete plans."

He said he's met Mike Huckabee, but he indicated he would be the first one cut from the short list of candidates he could support.

"Huckabee said he was in the business of miracles," Bloomberg said, referring to Huckabee's recent explanation as to why he's staying in the race despite trailing McCain by hundreds of delegates. "The dependency on 'It's just gonna happen' I know is not something to base an intelligent policy (on)."

FOX News' Judson Berger and Bonney Kapp and The Associated Press contributed to this report.