cuz pve is tehhhh gaynesss. im still #1 pvper on my server, and battlegrounds is pretty damn awsome.
theres to bit of a lack of raid content atm. theres the instances (which if your still running...you definatly arent a serious player) and the cap on the highest one is 15 ppl which is ubrs. then it jumps to a 40 man raid. NOTHING inbetween....wtf.
and on the other hand, the last 2 patches have been pvp based, the honor system, and now battlegrounds. so i assume the next bunch of patches will have plenty of pve content to make everyone happy.
all that said, i think being in a guild who does PVE and PVP on a routine basis is your best bet, i know on my server there are more and more pvp guilds comeing emergeing now that MC and onyxia can be routinely farmed easily if u have your strats down.....but being consistently good in PVP is a whole different ballgame. with much bigger bragging rights

Who cares if u have a full set of purple gear when another guild will just stomp all over you like its nothing.