Seems to take forever (literally) to load Online. It was stuck on 'Loading PlatinumQuest Online (6 of 6)' for a good 10/15 minutes - surely it shouldn't take so long, even for the first time it loads?
The issue seems to be some sort of deadlock in the networking code. If you experience the game freezing while downloading data online your only option right now is to restart the game. Some people have had success by trying multiple times to log in, others have not. I'm going to look into this as soon as I can.