I was thinking of something similar, though not identical, the other day, and that's the problem of hardware disparity and how that's likely to be aggravated in the coming generation.
Hardware disparity in terms of horsepower has become more pronounced with successive generations, and this generation more than any other, which is one of the reasons that the Wii hasn't been part of the whole multiplatform thing. Greater hardware disparity necessitates a greater shift in design and hrosepower between versions, which does not help developers who have been developing console multiplats since the nineties.
The problem here is that disparity in hardware doesn't look like it's going to be any less pronounced next generation. The potential gaps between release dates and differing corporate perspectives on the necessity of horsepower in pleasing the consumer (if you don't think Microsoft, Sony, and Nintendo have all learned lessons then you're wrong), all these and more will end up contributing to what may be the biggest hardware horsepower disparity ever seen.
This is problematic because the disparity will need to be designed for.
The only solution I can think of offhand, while maintaining some reasonable level of cost, is that every third-party game, when intended to be multiplatform, is designed with scalable assets.
Which means a PC lead for every. Single. Multiplatform game.
