Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Message beta stopped sending for me last night. See this thread. Is your's still working right now? I thought that Apple may have disabled for the ML update.

Same here. Mine stopped sending or receiving yesterday. I assume they are killing the beta with Mountain Lion coming tomorrow.
The thing is, the uninstaller won't work either. :(
 
It’s still working for me yes, just used it.

But I have to say, for the last couple of days, I have been having many problems with it, like messages sent from my Mac not appearing on my iPhone and vice versa, rare problems of notifications getting lost etc.
 
Even though it's well out of beta, still have this bug occasionally. Closing and reopening iMessage fixes it.
 
iphone 1 message showing

I finally had to open and close every message even old ones to get it to go away.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.