Well, I considered those but ruled them out for next generation on the following grounds:
Control schemes - we've seen already from Nintendo that you don't actually need a new console to graft new control schemes on. In fact, it is way cheaper (and less threatening to the customer) to graft them to an existing console, in fact the only reason Wii had to exist was because the Xbox360 and PS3 did - it was a competition thing.
3D - it's a technology problem. Domestic 3D is possible, but relatively crude, and to do muchbetter needs anotherchange in display technology - and it is too soon after the last one. Even so, this is probably the most likely driver, but I wouldpitch it around 2015 at the earliest.
Virtual Reality - partly technology and partly cost. The technology has the same difficulties as 3D, and the development costs would be even more stupidly high than they are now - which means essentially that consumers would have to put up with much smaller and shorter games (a bit like the cartoon shorts in the silent movie days) and I can't see that happening.
