I think it's a smart move--he was borderline in between rounds and had he been drafted in the second he could easily be cut if he doesn't produce--now he can hone his game in Europe and have the security blanket of having its rights owned by an NBA team. If he sticks his name in the draft still I think he's still a borderline pick, but for teams with multiple draft picks he could be drafted in the 1st round.
As I've said before, the guy just absolutely produces for a college player, and his smarts and savviness allow him to rank among the top in many athletic marker stats--among point guards, he's impressive in free throw attempts/field goal attempt, steals and rebounds per 40 minutes. Obviously those numbers will take a hit in the NBA because he's slight of frame, fairly unathletic and not that quick, but it's nice to know that he can actually do that. Even if he doesn't, his other aspects are great--he's just a highly efficient player who can either score for himself or create for others; only one point guard, Ty Lawson, finished above him in both assists/field goal attempt and points/play.
So needless to say he's a very unique player who has been a triple double threat as a tall PG in college, so that alone will garner him many looks at the end of the first round. Of course, many of those numbers will take a hit--all those athletic markers I've said above, and the scoring might too (he's probably not this good a jumpshooter--as attested by his very mediocre free throw shooting--and his ability to slash/get to the line will also take a hit)--but at the end of the day his ability to pass proficiently and produce effectively in college will still garner him tons of looks. But his athletic marker production basically says that he's smart and savvy enough to make those plays occasionally in the NBA (i.e. he has a nose for the ball, he's tough enough to slash and get to the line), so he'll have an easier road than most unathletic players.
If he does fall to the 31st (assuming he stays in the draft), he should definitely be someone we should consider (assuming we don't get Rubio). He does exacerbate the defensive problems that are found in our perimeter defense, but he's young, a pure point, and I think has the savvy to grow his way in the league (I do think he's different than most unathletic players). I don't think he's starter material so we should hopefully shop for a foil (a quicker athletic defensive minded guard in free agency), but he can be quite solid as a backup in the future, after he grooms himself in Europe for a few years.