It's been over a year since Blizzard began doing paid character transfers from server to server, and I'm still not sure how much of a success it's been.
On one hand, it's definitely changed the WoW environment. Guildless raiders can now apply to hundreds of potential guilds, instead of just the few on their server. People who rolled on a random server, only to find that their friends had rolled on another, can join their pals without having to relevel. And long-abandoned alts can finally be dusted off and brought into the light.
But there's a dark side to transfers, too. I frequent the Customer Service Forum, and a good number of the posts there have to do with unauthorized character transfers, character transfer screwups, or the like. (The rest of the posts are divided between "Why can't I swear in general chat?" "How can I become a GM?" and "Do something about the AFKers in Alterac Valley!") People are still unhappy that they can't transfer from PVE to PVP servers. And transfers can hurt. More than one guild has broken up because some of its officers decided to ninja-transfer to a better guild, sometimes taking the guild bank with them. People transfer in anger and then realize that they have to wait a long, long time to come back -- or sometimes can't come back at all.
I've never transferred, and probably will never do it. In spite of the idiots, trolls, and ridiculous flame wars, Magtheridon is my home server, and I'd feel lost without any of the people I've grown to know over the past few years. Have you ever transferred? What do you think about the service?