Travis d'Arnaud came over to the Blue Jays in the trade that sent Roy Halladay to the Phillies. Last year he had an OK season in A+ ball but this year in AA he's really starting to take off.
d'Arnaud is posting a very solid .232 ISO, he's always had solid power but this year it's really starting to come on. His .393 OBP is above and beyond what one would ask out of him, as is his .420 wOBA. He could improve his eye at the plate, his BB% is 7.9%. If he could bring it up 2% or so that'd be ideal. His 20.4% K% isn't awful as long as he still supplies power. d'Aranaud's 161 wRC+ is 61% better then his league's average, a crazy number that probably isn't sustainable. It's no secret that he's had help based off his .383 BABIP so regression to the mean is definitely expected.
d'Arnaud is only 22 so he has a little more room for improvement but at the pace he's at he could potentially see time on the big league club in 2012 and if everything goes right he should be the starting catcher in 2013.