Bless the folks at www.gscentral.org, one of the hackers have found a way to play the levels online.
http://www.gscentral.org/bb/viewtopic.php?t=764 (Look at the second page)
http://mmii.info/misc/ticktockclockwifi.avi - Tick Tock Clock Online w/ ShakyCam(TM)
However, I'd advise to you folks not to bother the guy who discovered the exploit because hes been doing this all day.
Not just the levels like Bowser's Castle can be played online, even the battle levels, which sadly cannot be properly played online; the game still acts in race mode, and cause some freezing problems.
Theres no real problem playing them on your end, but things like the long pipe that shoots you up in Waluigi Pinball will look odd when you see the other players as they look like they fall through the floor, but the levels still play properly despite a few hiccups.
All I played online was Bowser's Castle, but the guy is so out of it that he just drives backwards.














