Whatever the specific rates are and regardless of the problems fixed with the new slim (Can anyone provide an accurate failure rate for the slim? I was thinking of buying one eventually, as they're getting pretty cheap.), my point was simply that the 360 came out, and remains in the case of non-slim versions, a bit of an unreliable platform. If my only choices for next-generation consoles are to accept some abnormally high failure rate or wait several years for reliable slim versions of said consoles, I'm not too sure I'm all too keen about next-generation consoles. The point to this is I'm wondering about what you think we can expect from next-generation consoles in terms of reliability. How large do you think they will be? My PS3 slim is most certainly larger than my PS2 slim.
Larger still. Like others have said it's hard to squeeze better tech into the same sized box, because of the extra heat it will generate. It's also cheaper to produce larger components too. In regards to the reliability, we won't really know until they are out, but one would hope both companies have learned from their mistakes this time round. Whether or not they have remains to be seen, but one would hope.