I think this is probably a better exercise to go through now as opposed to after the draft. The status of the top guys should not really change from right now to Jan/Feb 2013. Giolito has a chance to improve/hurt his stock quite a bit I suppose, but other than him, we should be able to figure out roughly where these guys should slot next year. We have a chance to be realistic about it now, before bias sets in, though there might be some bias toward the whole group getting high rankings.
Here are my guesses...I don't want to get into too much detail over the explanations right now, but I'd love to see other rankings and maybe we'll get into some detail later.
22. Byron Buxton
29. Carlos Correa
35. Mike Zunino
43. Mark Appel
55. Kevin Gausman
There are a few other wildcard types (namely Giolito and Zimmer) that I haven't ranked here, and I wouldn't be shocked to see one or two of them crack the top 50 possibly. I these are the consensus top 5 at this point. This is how I think their general industry ranking will shake out.