They wonderfully communicate, too, but of course the primary and fastest way is their facebook and twitter. Lots of us are tracking these and they are really working on things.
Trading Post - they had a successful test with random invites of about 15% of the population allowed in. If I read this right, it should be open to everyone now. I just have to log in yet today to prove that the cute little Quaggan is not still in snooze mode. ;)
In game mail had an issue and though they fixed it, they see a potential for in-game mail to possibly be linked with the email phishing. Didn't really understand this, but they are taking NO chances even with a pin hole possibility in this area.
The group and guild issues actually are intermittent and there may be quite a few large guilds, but on average there are not many that tried to push the envelop like we did in the first hours of head start. So look at the guild issue as another way Gaiscioch helped break a game so the developers find an issue. We came REALLY close to the number in beta at which Gaiscioch got broke at. So we almost had a chance to see if it broke in beta, but we were within 10 or so short! Go figure. ;) Anyway, intermittent problems are way harder to diagnose and they were the trouble tickets I HATED because you would spend HOURS trying to find some wonky and usually simple thing. Example - customer always losing connection at 10am - they made new pot of coffee at this time and the network and coffee pot were sharing a power strip and it would have brown out issues. So sometimes it gets strange. ;)
So be patient - if you have a "bug" in the game. Do report it with as much detail as you can think of. They DO read these things and do their best to keep us in the loop with their chosen methods of communication.