I've noticed all the players in the draft are 22 years old (at least I haven't seen otherwise). In reality though, the NFL draft has players whose ages range from as young as 20 (which isn't very common) to even 24 year old's.
I think it would be kind of cool to have that extra wrinkle when drafting. There may be player with really good skill but he is 24. Or maybe there is a 21 year old who doesn't have the greatest potential but you take that risk because he still has a lot of years to develop.
Just an idea.