In order to properly complete the R&D necessary to create a console it usually takes several (as in 3 to 5) years for most companies ... This doesn't (necessarily) mean that they're looking at final hardware, but I suspect that they're dealing with their partners (Panasonic, AMD/ATi, and IBM) and looking at their semiconductor (and other hardware) road-maps and trying to plan the type of system they will produce.
It's surprising that people forget that the first news/rumors of the Cell processor actually started comming out at (roughly) the same time as the Gamecube/XBox were released ... Sony's (insane) early discussions about it was that the combination of high speed internet and highly parallel code would enable users to take advantage of the idle cycles of other PS3 owners consoles to produce amazing effects in game; the term Cell was used because it was supposed to represent a single cell in an organism.
