Both Dave Berri and apparently John Hollinger (I don't get ESPN insider, this is via Matt Yglesias) are speaking highly of Ty Lawson's chances in NBA; Hollinger has him as he best player in the draft behind consensus top pick Blake Griffin, and Berri's numbers list him as the best point guard in the draft and third overall, behind Griffin and DeJuan Blair. The number-crunchers are pro-Lawson, the more holistic folks, like Chad Ford, put him in the bottom third of the first round.
The biggest knocks against Lawson seem to be a) his size, and b) that his stats are inflated by playing amongst the talent at UNC at the speed they run at. The first is somewhat valid, but doesn't explain the draft watchers' love of Johnny Flynn, who is also 6'0", and posted significantly worse numbers for the Orangemen this year as a sophomore. The second objection, to anyone who watched a lot of UNC games this year, is pretty ridiculous. Playing with the offensive threats he did may have inflated his shooting percentage and added the occasional assist, but where Lawson really draws attention to himself is his lack of turnovers. His ridiculously low number compared to other point guards on that score came despite the breakneck pace he and the Tar Heels were running at, a tempo that would lead you to expect more turnovers, as they have less of a deleterious effect on your team's chances. That, factored in with Lawson's speed and strength, makes him a better prospect than a lot of people are considering at this point, and definitely more likely to succeed than similarly sized guards like Flynn and Darren Collison.