Just being real here..
Horde side ranked pvp is pretty close to dead. I spend hours in trade looking for arena partners, for 2s, 3s, 5s, any comp, etc. It's just not active in that regard, RBGs are the same way. I know of some RBG groups that run, but a lot of the people I've met have been turned off by the people running them, resorting to either trying to start their own group, or just not running at all due to lack of people, or at least lack of people you'd trust on your team in an RBG. It's an unorganized mess.
World pvp is frequent, but horde get steamrolled because 1/10 will respond to it, the others will sit on their mounts and let it happen. Horde guilds often collaborate with alliance guilds to organize pvp if that's your thing, but that just doesn't have the feel that spontaneous pvp has.
I generally run BG groups with off server friends, and we tend to win the majority of them, as far as just random groups go, it's a toss up, but like Trex said, you'll generally get a queue within 10s or so which is great.
Overall, I'd recommend not coming here. Most of the people here will obviously disagree, but if I were transferring I'd want to know this stuff. As far as the people here go, I really can't say anything negative about anyone on Veco, they're friendly, welcoming, all that good stuff.