Hi Voryl, if you haven’t yet, you may want to scroll through the BB Guild Directory here: The BB Guild Directory
I recall there are some guilds with an RP theme who also raid and as Maley said, many raiding guilds who are RP-friendly. If you hang out in Stormwind you will see many 60’s decked out in raiding gear who also have detailed TotalRP descriptions – they would be the people to talk to if you choose to transfer here.
From Karazhan through Deathwing I was fortunate to be an officer of a 10-man RP raiding guild – I was just reminiscing with our guild leader last week about what an experience it was. Our raid nights were our RP events – sometimes we would meet in a tavern beforehand, but a lot of our roleplay happened in the instances and afterwards, and out of game in various blogged stories. The leader of our merry band was an exiled Arathi noble and fury warrior — once, he and Lorith got into an argument during some downtime in 10-man Onyxia, leading to a short scrap that lost Lorith a tooth, which she later had replaced with an Azerothian diamond. Roleplaying in the raid like that was just always a great way to add color to the evening.
I don’t know if I’ll ever be up for the dedication of raiding again, but I mention that example in the hopes that others out there are doing the same kind of thing within their own raids. I like to think that on an RP server, players are always at least on the edge of being IC when the opportunity arises, and RP is at hand more often than we think while we are running around pressing buttons.