I think that the fact that Wallace has been traded 3 times in about a year reflects very poorly on him. He was the key piece in the Holliday deal, but has been traded twice for players that most places rank lower than him--that suggests that Oakland and Toronto both saw something that they didn't like about him.
You'd have to figure he can't field or is a head case or something, because judging by his numbers at the plate he seem to be major-league ready. In 714 AAA At-bats: 299 Avg 357 OBA 33 HR 45 2B 484 SLG 165/56 K/BB is not so hot, but ...three times in a year? Even if Berkman isn't traded, this kid will probably be hitting in Houston soon.
He's signed thru till after 2011, and there's a strong chance he could accept an extension if the Phils perform well, which they will.