Rasmussen is out with a new survey of the Dems in Iowa (Nov 26-27, 1,156 Dem LV, MoE +/- 3.0%) , and he shows an ever so slight tightening in what remains a three-way dog fight:

Clinton 27 (-2 vs. last poll Nov 12)
Obama 25 (+1)
Edwards 24 (-1)
Richardson 10 (nc)

Overall, Clinton's lead in the RCP Average for Iowa is down to just 1.2%, and the trend lines look favorable for Barack Obama:

And, as with the Huckabee-Romney flip on the GOP side, Intrade now has Obama as the favorite to win Iowa, with his contracts trading at 50.0 to Clinton's 45.0.