I noticed it first with the RR hall outside of Lerilin, then again with the Mirith Vanguard Hall, it appears that with the July 2012 patch the Guild Hall signs have vanished. I don't know if this was intended, or if it is just me for some reason, but it would be nice to have them back so we can tell where the temples and stables are.
Guild halls signs aren't related to the server build. Sounds like the server restarted without Jinker or I around to take care of the signs. One of us will take care of it this evening.