From what I've read the surgery Ozwalt had to correct the groin problem has a very high success rate. He was lights out even with the groin issues. If this surgery eliminates them as has been reported, then Oz could very well vault to the top of the NL pitching list.
Here is a case when drafting early hurts. If you are drafting later, say mid-March, you will have time to see Ozwalt and read some more reports before deciding, but I would take him pretty damn early myself. I would call him a top 10, with a chance to be a top 5 pitcher.
Eternal vigilance is the price of integrity.