I have only heard great things about him via Vicki McKenna (one of our resident conservative talk radio personalities).
Other than that I can't tell you much, but he was chairman of the republican party of Wisconsin, and we *did* manage to turn from a blue to a red state (pretty handily) and unseated Russ Feingold, so he must be doing something right. (pun not intended, but it works)
I think he should be able to do wonders for the RNC.
Certainly couldn't do any worse.