Middlebrooks has made great progress, but I wouldn't say that he has done wverything that he has needed to do in the minors. I have seen better prospects than him (Hanley Ramirez comes to mind) regress while in the minors. Middlebrooks needs to play well again this season to prove that he can be consistent.
As for Youk's, if he doesn't stay healthy and have a good year in 2012, I don't see them exercising his option.