Dean will stay the same, although between last night and today he got the bitched slapped all the way back to where he was in 3Q last year, the Q where many americans fell in love with him (Announcement, Sleepless Summer). That was the Howard Dean I like, not the Howard Dean after he started getting endorsed.
The "speech" is a one day story, I don't see how it will have any impact Friday. There were worse days in Dean's campaign (Osama not guilty), and now the spotlight will be on Kerry, where he will wilter like he did before. The SOTU ends all this coverage of the speech.
Kerry's polls will rise and it'll be a hard fought tie in NH. Edwards will go nowhere in NH, since he was relying on negative-ad-backlash in Iowa. He'll get up to 10% maybe! Kerry/Clark/Dean will be bunched together, allowing Dean to claim a comeback from a week of negative coverage, and onward to Febuary 3rd, where he'll kick ass in the southwest and Missouri.
Dean is electable, there were worse things for Bush in 2000 (ignore ideological differences), Gore in 2000, Clinton in 1992, Regan in 1980. The "speech" has no lasting impact, except for adding the phrase "Get Howard Dean fired up!" into the lexicon (thank you ESPN).