When do they put the post card up for printing? I know these thigns vary, but I've always just printed mine out as I was running out the door. This year I need to get printer access from somewhere else though, and have school/work more or less all the time until the con, so I need to actually think of these things.
No current ETA, but obviously before Thursday.
Sorry that I can't really give you a better answer. :( I'll update (or someone will post) when we get more information.
If it came down to it (providing you're staying at one of the con hotels) you could probably use the business center at your hotel to print it, then run down to registration.