It looks like ESPN updated their 2013 basketball recruiting rankings. All 3 Michigan guys make the list:
Zak Irvin-21 (3 away from 5 star status)
Derrick Walton-32
Mark Donnal-97
Both Irvin and Walton moved up, while Donnal took a fairly significant tumble. Michigan also has the top 2 commits in the big 10 at the moment (although people think MSU has a pretty good shot at #1 overall Jabari Parker). Another great year for Beilein in terms of talent evaluation.
http://espn.go.com/college-sports/basketball/recruiting/playerrankings/_/order/true