Here are some candidates and their profiles:
I didn't include guys I think will not be there (Babbitt, Bradley, George, James). I'm not even sure some of the kids I mentioned will be available.
Personally, Ebanks is a guy I'd take. He's a long combo forward who has the potential to become an extremley versatile defender, similar to a Jared Jeffries. I'm not his biggest fan, but I don't think you can do much better with the 27th pick, he has some potential and would fill our needs. And he's a very good passer.
There may not be much better prospects than Warren at #27 (if he falls there), but we have enough guards (esp if we land Wall or Turner), and like NI pointed out:
Warren had a weird year. He decided against leaving OU a year ago, when he would have been a top 10 pick. Instead of earning $2 million in the NBA, he spent 2009-10 battling with his coach in Norman, getting a reputation as a selfish player and to make it all so much worse, having a disappointing year on the court. As Jonathan Givony of Draft Express writes, "His 2-point percentage is down 5%, his 3-point percentage is down 6%, his turnover rate has nearly doubled and his assists and scoring are only up slightly in turn."
Some of the other guys could be available at #31. I wouldn't take Lawal even with our 2nd rounder. I don't think he will be better than Boone. Yeah, he is a good rebounder, but is very limited, is a poor free throw shooter and a bad passer.