Prediction: despite all his naysaying, it'll happen before the end of the summer. He will garner the far-left, MoveOn, antiwar, and Hollyweird support, and will soundly defeat the 'Beast and Osama-Obama in the 'Rat primaries.
Algore will be a much more formidable candidate in the general election than anyone else the 'Rats have to offer. The DBM will see to it that all of his insane sore-loser ranting over the last 6 years will conveniently be ignored, flushed down the memory hole and out of sight and minds of the sheeple who don't closely follow politics. If Iraq is still on the table next year, he will win. Mark my words ...
I think you are right on the money. Gore is an '08 stealth candidate. He has been traveling the country garnering support for the "global warming" movement from grassroots people up to billionaires like Richard Branson, Ted Turner and others. They have been flooding schools and churches with his movie. His climate movement can be rapidly transformed into a "Gore for president" campaign at the right time--like you say--probably August or September. The problem for him is that if he positions himself to the left of Hillary he is another Howard Dean.