I think there's no chance to see XBO delay due to the problems they are having. IMO, I think MS would rather have another RROD fiasco and have another 360 like console in terms of sales, then launch later and another XBOX in terms of sales. Whether or not they can recover from another RROD fiasco, especially since Sony is launching very close to them this time, is another question.
They'll ship with next to no units which will create demand in itself.
Yes and no. It would be 100% true if the PS4 wasn't launching at the same time, but as is I can see a scenario where a customer goes looking for XBO in order to play the latest COD, Battlefield, Madden, Halo and, after finding out about the supply constraints issues, walks out with a PS4 to play all those games sans Halo - which a customer could overlook if the mention of a 2000 player per map FPS MMO game will come exclusive to PS4 and is free to boot.
2. Supply Constraint: Loss of early adopters, but Sony has shown that you CAN recover from that.
3. Launch Delay: See #2 but to a greater degree.
PS3 was never as supply constrained as the Wii or even the 360, but I see your point. It took Sony a LOT of money, man power, exclusive games that are better looking than 360 games, and energy to get the PS3 out of its funk to where it is now. Even then, I would argue that Sony just recovered from mediocrity, destined to doom to decent levels of sales. Playstation went from 160 million to 80 million, even after all the effort made by Sony. That's definitely not a position MS wants to be in.