Heh i never knew about something like that,sounds very interesting "maintenance mode" :D I hope x360 will be hacked without LoZ:Twilight glitched saveThere's also X, or the unknown; info gets leaked all the time, and you never know when somebody high up, I dunno, gets drunk and spills the beans.
As far as tricking the 360 to open in a hacked dash, let me point you in the direction of something called the Twilight Hack. If you don't know what it is, then I'll save you the google search. Twilight Hack is a very old Wii hack that involves Twilight Princess (Zelda) and a modded save. In this save, your horse's name has been modded to be an insanely huge amount of letters long; the save puts you in front of a man, and when you talk to him he references your horse by name, which causes the Wii to overload and go into maintenance mode, where you can load any software that is compatible regardless of security clearance (ie, the Homebrew Channel). For a long time, this was THE way to soft mod your Wii.
Now I'm aware that the Wii and the 360 are totally different platforms, as well as I am aware that the 360 not only has intensely better security than the Wii but it updates with entire platform changers (as opposed to the Wii, who's updates consist solely of ways to keep people from hacking it). But if there were a way to similarly open the 360 in maintenance mode, then all we would need is a single program similar to Wii's Homebrew Channel. Basically, HC's only purpose is to allow homebrew software to install through another program that is already on the Wii (HC itself) which allows the software to bypass security check.
If the 360 could get a similar program that serves a similar function, as well as find some way to boot it without a hard mod (similar to booting HC through Wii's maintenance mode) then the rest ought to be easy peasy. It's just that initial hard part that's the problem.