When you commit to producing a console - both its hardware and OS - at any point in time, I imagine it would be very hard to predict where technology (and consumers expectations) would be 8 years into the future. Nothing is future proof.
I've owned almost every console that has been released in the UK over the past 20 years and for what the 360 gives me I'd put it right up there as one of the greatest, if not the greatest that I have ever owned.
I imagine in another 8 years we'll be discussing the frailties of the soon(ish) to be released PS4 and MS consoles.