Generally when major minecraft updates come out (I'm talking from 1.1 to 1.2.x, not 1.2.2 to 1.2.3), most wait to update as the bukkit folk take time to make sure the next RB is useable. (A RB is a "stable" server build, 1.1-R6 refers to the sixth 1.1 recommended build. There currently isn't a RB for 1.2, otherwise most servers would have upgraded already.)