I watched the entire presentation this afternoon on youtube. (searching for 25c3 there will find it). iirc there was 8 parts and the demo of BootMii was in the last or penultimate. They don't show much though, but its still worth a look and I certainly understand things like the IOS and NAND a hell of a lot better now.
The thing that got me was the shear lack of questions at the end. I would have asked a million. The only poignant question asked was when will BootMii be finished - with the standard reply; when its ready.
IMHO if you have some spare time and are even remotely interested in Wiibrewing then it's definately worth watching the presentation - and the clip from 24c3 as well just to see whats changed in a year - Bushings haircut hasn't :P
cheers