Rasmussen tracking poll. It's a 3-day average, and today's poll includes 2 days since the last debate. Yesterday's poll, which had 1 post-debate day in the average, had Romney at 49% and Obama at 47%. Romney lost 2 points with one more day in the average.
ADDED: On the other hand, Romney has gained in the swing state tracking poll. It's now 49% Romney, 47% Obama. Yesterday, it was Romney 49%, Obama 48%. The previous day, Obama was up by 3 at 50% to Romney's 47%. That poll is a 7-day average, so there's less post-debate polling in the mix, which may make the trend toward Romney more surprising.