As Mark noted below Huckabee is showing as the Iowa leader in the Zogby tracking poll as well as the averaged ClearPolitics polling here: http://www.realclearpolitics.com/epolls/2008/president/iowa-primary.html
The MSNBC poll they discussed today showing Romney in the lead is listed at ClearPolitics as Mason Dixon, but as I've noted before poll averaging is probably the best measure assuming all the polls in the average are unbiased. Averaging can fail miserably if you include polling that is not objective - e.g. polls by groups with an agenda or axe to grind. I have no reason to believe any of these fall into that category.
Huckabee's press conference today was the talk of the media at MSNBC who suggested he was trying to be negative without running the negative ad he'd planned. It'll be interesting to see whether Romney or Huckabee can master the art of being very negative *without acting like you are being negative*. Both are working hard at that during these last few days.
Some polls are showing Obama over Clinton where MSNBC had almost a dead heat. It'll be fun to try to untangle some of this data over the next few days, though our predictions remain as Clinton and Romney with Iowa Victories.