While it would be cool to have the show in a real concert venue, I can somewhat understand why they aren't. I hate to be so blunt, but I think this might be for the better. I'm really curious to see how many really go to their concert. I'm sure it'll be a reasonable amount, but generally, people who are into anime but not jpop tend to think idol groups like MM are gross. Oh well, if nothing else, it just means there's more room for us fans.
It would be cool if they wait till 10AM PST to do the registration. I'm not fond of logging onto my banking stuff at work. Being the network admin, I know how horribly unsecure it is.
Edit to not double post: Looks like registration has been delayed. The post on AX's forum says "sometime this week" again.