I don't want to be a broken record, but I put a pretty decent explanation here:
World of Warcraft - English (NA) Forums -> Wow Stuck at Connecting
While I couldn't originally find the proper config to make the change, the details should help someone at Blizzard sort out the apparently incorrect internal default value(s) for the realmlist.wtf file when it is missing.
It may not relate to everyone's issue, but it certainly is a problem. If I yank that file, WoW won't replace it, and it tries to connect to "enUS.logon.battle.net" which is incorrect or old. This needs to be changed in WoW code I would imagine.
Also, a quick DNS record update to "enUS.logon.battle.net" to match the "us.logon.battle.net" would be a fast solution requiring no user interaction at all. Unless that domain is going to be used elsewhere, no harm done right?