Mitt Romney, who was given a coveted Friday noon slot to speak in the main hall, where he was introduced by Senator Scott Brown, 21%. Sarah Palin, 3rd at 7%, and Tom Pawlenty 4th at 6%. Of the 10,000 registrants, 2,400 voted.
I didn't vote though I could have. Voting booths were set up in the halls on Thursday and Friday at th entrance to the main exhibitor's hall and elsewhere. So my interpretation is that this was a straw poll of those who HAVE an opinion about an election 2 years away.
The CPAC2010 hierarchy is likely to downplay this result and provide little background data (e,g., what percentage of people in attendance voted in past years).