The honest truth is that I have no idea what to expect of Carlos Quentin in 2010. The good news is that he's only 27 years old, and that as bad as his injury plagued 2009 season was, he still was on pace for 30+ home runs if you project his at bats to a full season's worth. He also rarely strikes out compared to most sluggers, giving him added value in some daily contest formats. After going in the third or fourth round of drafts last year, he's ranked 114th by ADP at CouchManagers.com right now.
That said, there's plenty of bad news. First of all, he's never had 500 at bats in a season. So injuries may just be part of the package with him. Even in his terrific 2008 season, the low strikeout rate didn't lead to a particularly high batting average (.288) and his average in the majors other than that has been really poor. Quentin hits remarkably few doubles for a slugger. He also doesn't get a lot of walks or triples. Those characteristics may actually hurt him more in daily contests than in traditional leagues where those statistics don't count.
If he really falls below pick 100 in your draft, then I would classify Quentin as a draft day steal. But he's definitely a fairly high risk player. In general, I'm hesitant to consider a player's potential trade value when evaluating him, but I do think that a resurgent Quentin would be perceived differently than equivalent players. For example, if Quentin is hitting .300 with 18 home runs at the All-Star break, he could probably bring a lot more in return than if someone like Nolan Reimold does the same.