Blizzard's Senior PvP Designer Brian Holinka has taken to Twitter to make an announcement about just exactly how PvE gear is going to work in PvP come patch 5.4.
.@anthonydeluca8 It won't. The ceiling will slowly go up next season (e.g. 1 point per week) but PvP gear will be exempt from the ceiling.- Holinka (@holinka) June 13, 2013
As Holinka has mentioned in the past, they want PvE gear to catch up to PvP gear slowly. And it makes sense, nobody is able to step into a season and be fully conquest geared in the first week. So, a player in PvP gear's average item level will probably increase in line with that of a PvE geared player, with the notable difference that, of course, PvP players will have PvP Power on their gear. It's also worth noting that this scaling occurs only in PvP instances, so arenas, battlegrounds and rated battlegrounds. Whether it will take PvPers 26 weeks to become fully geared remains to be seen, but it will feel good for PvP gear to be decently ahead of PvE gear for a while at least.