I know that many other people have been having this same problem. I'm on the mac client by the way. I can log in fine, world and channel select all works fine. Once I try to enter the game choosing my character, the screen turns black for a second then exits out. I get an error message saying "Game has been disconnected, please check server status or blah blah blah" It's been going at this for about 3 days now. Any suggestions? Thanks.
This usually means the server is having some problems. Keep an eye in the Chatbox and forums for updates.