I hope he comes back for his senior year as there is still room for lots of improvement with his game, but my perspective is as a Duke fan and my opinion on whether he is ready or not is useless. Here is what the mock drafts predict:
1. Draft Express has him going at #22:
http://www.draftexpress.com/nba-mock-draft/2012/
2. NBA Draft has him going at #22:
http://nbadraft.net/2012mock_draft
3. My NBA Draft has him going at #18:
http://www.mynbadraft.com/2012-NBA-Mock-Draft
4. Hoops Hype has him going at #26:
http://hoopshype.com/draft.htm
I took a look at the 2011 draft and the #22 pick was Kenneth Faried who is earning $1,254,720 this season. In 2010, Elliot Williams was the 22nd pick. Williams is earning $1,348,800 this season. Mason's decision will most likely hinge upon whether or not he believes he can significantly improve his draft position by returning to school. One intangible is perhaps Mason enjoys school, he is an Academic All American, and will come back for his senior season to finish his degree. Or perhaps he desires to play one season as a Blue Devil alongside his younger brother Marshall. As a Duke fan, I really hope to see Mason lacing up his sneakers in Durham for one more season, but perhaps I'm simply being selfish.