The poll is an online poll commissioned by Reuters and conducted by Ipsos Public Affairs. It's the same outfit doing the Reuters/Ipsos daily tracking poll. It's using the same methodology but it's separate from the daily tracker.
The upshot is respondents think Romney won, it did move his numbers and it did move the head to head. But not dramatically.
Who won the debate? Romney 50%, Obama 28%
More or less likely post-debate to feel more positive about Mitt Romney? More favorable 27%, Less Favorable 19%. For Obama, it's 16% more fav, 18% less fav.
Head to head among Likely Voters. Predebate Obama 48%, Romney 39%. Post-debate 48%, Romney 43%. [see update below -- the pre-numbers may actually be 47-41]
A 4 point move for Romney is substantial. But what's notable is that Obama's numbers didn't move. Romney picked people up. Also note that Ipsos had Obama with a 9 point lead pre-debate, which is much bigger than most polls have at the moment. The current PollTracker Average has a 3.6 point lead for Obama. So if you put a 4 point jump against those numbers it would put him back into a tie. But those kinds of apples to oranges comparisons don't make sense.
We'll have to wait for more data. But this first sounding suggests a move for Romney but not a game change.
Late Update: WaPo blogger and TPM alum says on twitter that the pure pre-post comparison is 47-41, 48-43. The issue seems to be that the pre-number included a few days leading up to the debate rather than just the day before. (Indeed, the polling doc gives 9/29-10/3 as the polling dates for the "pre" numbers.) So if you go with the immediate before and after the spread is closer. Greg doesn't give a link. But if Greg says it, I'm sure he's got it sourced.
Later Update: I encourage people to look at the crosstab data in the poll. A number of readers have written in that the internals actually show Obama gaining ground in a number of cases with independents. I would only caution that numbers from subgroups often have quite high margins of error. So I wouldn't read too much into them, though certainly they weigh against the idea that Obama was badly damaged.