Okay as OP, I've given this some time and distance. Read all the posts and I've changed my mind.
1) Was it a dirty play....no. Tejada should not have turned his back. I believe this led to his injury because he didn't know where Utley was.
2) Was it a hard nosed play....yes. Have there been worse take out slides in the history of baseball...yes. If Tejada had not turned his back I think this injury could have been avoided or Utley would have got a face full of cowhide.
3) Did MLB overreact....certainly. That is what they do. They'll have time to figure it out in the off season.
4) Does there need to be a rule put in place that prevents someone sliding into a MIF past the bag.....yes.