wouldn't replacing the mobo be missing the whole point entirely? you really wanna pay $99 for a small clamshell case, IR keyboard and a passive matrix lcd?!
In my opinion the whole point of this is 1)it skrews MSN out of an expected subscription, 2) the hardware is worth twice what we (those who got it for $99) paid it for, and 3) you don't need to be big and bad to be cool, check out the threads with all the ideas for uses. we're not going to play diablo on this thing...
it's one persons mp3 player,
another's auto-pc (cpu fitsin a glove box and the raw lcd looks great bolted to the dash),
my girlfriends cookbook,
a web terminal (gee, that's an origional one, hehe),
a really big alarm clock with silly animations done in vga mode 0x13,
a network access point that fits in your bathroom (for those who like a 'puter in every room),
a digital picture frame...
i could go on, but my point is, 1) you replace the mobo, and it's no longer an IA1, it's a whatever-small-mobo-you-get machine stuffed into an IA1 case (i dunno, but that doesn't sound like a hack as much as some creative bashing, soldering and wireing) and 2) it's not always about power, it's being creative with what you have to work with, that's the whole fun of it.
of course, i could be totally wrong and everybody has the right to their own opinion, but that's my 2 cents. feel free to do what you will, but slapping a new mobo in rather than finding a way around the bios just sounds like a cop-out to me.