show new status after really changing it, not before
if you are "online" and want to set your status to "away", you get this window to set your status msg. but when this window is open, your status below the roster is already set to "away", but your real status isn't changed. when you change your mind and click cancel, the status is changed back.
but since you didn't really change your status until the time you click ok, i think the status below the roster should stay the old one until it is actually changed.