In a follow-up to the lengthy Badge and PvP point preview for Cataclysm, Bornakk posts that weapons for PvP will be tiered much as normal and heroic drops are in current raiding.
Bornakk - Cataclysm Badge and PvP Point Changes
The lower tier weapons will correspond in quality to items found in the latest raid tier on normal difficulty and cost only Conquest Points. The higher tier weapons will correspond in quality to items found in the latest raid tier on Heroic difficulty and will have a minimum personal rating requirement in addition to costing Conquest Points. All of the highest-stat PvP armor, including shoulder and head pieces, will cost only Conquest Points and have no rating requirements. We have updated our original announcement text to reflect this clarification.
This basically means that while the best weapons will require success in Arenas and Ranked BG's, PvP players will be able to get weapons upgrades via running PvP out of the gate rather than having to hope for an instance/raid drop. It also means an end to armor pieces, trinkets and other items requiring a rating to purchase, making gearing up for PvP easier. It seems likely that this change is aimed at making PvP easier to start in and taking some of the perceived need to PvE away from the PvP game.