The most recent Gallup poll shows that Huckabee, Palin, and Romney are in a virtual dead heat at the top of the GOP preference for 2012 presidential nominee:

Republicans and Republican-leaning independents have no clear favorite for the party's 2012 presidential nominee at this point, with Mike Huckabee (18%), Mitt Romney (16%), and Sarah Palin (16%) in a statistical tie for the lead. They are the only candidates in the crowded field of potential candidates who register double-digit support.

Minnesota Congresswoman Michele Bachmann, and former Utah Gov. and current Ambassador to China Jon Huntsman were included for the first time and received 4% and 1%, respectively.
New Jersey Gov. Chris Christie, who maintains he does not plan to run for president, is still volunteered by 1% of respondents, as is Indiana Congressman Mike Pence. Pence's name was included as an explicit option in previous Gallup surveys but he recently announced he would not be a candidate for president in 2012. South Dakota Sen. John Thune, who announced on Tuesday he would not enter the race, also gets 1% of the vote.

The results are based on interviews conducted Feb. 18-20, with 1,326 Republicans and Republican-leaning independents on the Gallup Daily survey. Gallup had previously asked Republicans for their 2012 nomination preferences in November and September.

Those earlier polls also showed a top tier consisting of Romney, Palin, and Huckabee, though Huckabee trailed Romney (by a statistically significant margin) and Palin in the September poll. Huckabee's support has increased in each of the subsequent updates, and his total six-point gain since September is the largest for any of the candidates to date.

It should be noted that nobody in the GOP field has officially announced their candidacy yet. The political situation is so unsettled that both Huckabee and Palin are probably seriously considering not running as much as they are looking at taking the plunge. 

Somehow, I think the eventual nominee will not come from the three frontrunners in this poll.