It's a bit of both, actually. It did work at some point, but it's always been under heavy development, growing features, dropping other features, and so on. It was pretty handy when it worked, aye. Especially since it was the only means of contacting people directly. The support for offline messages was there, and it worked flawlessly. It didn't, however, notify the addressee of new messages by e-mail - so they'd have to log in to know of those messages anyway. Nor is there any means to e-mail other users (which probably has to do with privacy concerns), sadly.
I was given an estimate of five days to a week for the chat to come to life again. Fingers crossed.