I think it's a fairly common procedure. You develop a game on PC after all and you need a strong PC. Later comes optimization for less capable hardware. Games they have shown are 6 months far away from being finished.
Of course, they won't talk about it in public because average gamer is a dumbass and it's hard to explain anything to him.
Yes but usually they try to demo the games on a PC with a similar spec to what the console will be capable of. At least that's what I'm told by the devs who frequent overclock.net. These guys at E3 were talking up the graphical power of the xbone while running it on a 780...which is considerably more powerful than what the xbone will be capable of. Struck me as shady.
Not that I ever had any intention of buying a xbone anyway. The PS4, however, is sparking my interest. The way AMD designed the core will allow it to do things that current PC's can't. At least for the next few years. You probably won't see it fully utilized with launch titles but after six months or so, when game developers have a handle on the architecture, the games should be interesting. But I won't be buying that at launch either; they don't have any must-play titles yet. Wii-U may be the first "next"-gen console I buy if Nintendo can get their shit together and provide me with my Zelda and/or Metroid Prime fix.