Sorry, but I am max level on classic and just find myself wanting TBC more and more. Those arenas were one of the best additions ever made to the game. World PvP was very much alive as I engaged in tons of it while farming my epic flying mount. The above post about fighting over resources is very true. You are right that homogenization happened as a result of arena, but the affects of that was felt in future expacs, not in TBC itself. in TBC they put arenas in the game and then were like "well shit, this is hard to balance." The imbalance of TBC actually gave it some charm imo. Far as BGs I did a shit ton of em.
TBC was classic done right. If it comes out then the classic servers will lose a fair bit of their population because BC will prove to be better. Maybe this is what you are afraid of since you prefer classic and know the majority would disagree with you.