It's a good idea to use Global Chat, which you can access from the menu strip in either client.
Help channel seems to be the more popular one on Oceania. It's not exactly bursting with people as not everyone uses it and I would guess like any online forum most people lurk. You can get a sense of what people are doing, though, from the more vocal users. I've seen people use the chat channel even though they're bunched together in the same place, so it looks like the preferred means of communication now. And of course, getting into an active guild doesn't hurt at all.