Well, I have to base my gues to rumours... Win 8 will be first pure 64 bit Windows, maybe pure UEFI support, maybe they have to drop old legasy support. so that they can make better OS than win 7 is...
All things that most home users only find good thins to happen, but the big companies, universities and so on big corporations may not be happy if anything mentioned above happens. It would make win 8 an risky product, because many "big money" customers would leave win 8 and stay in win XP, win 7 bandwagon as long as there will be support... We can see this allready in Win XP situation vs Vista and win 7. And win 7 is relative "friendly" towards older hardware and software (after some upgrades at least) Win 8 can be different beast in that sentence.
Version 2: MS may at last go to pay one time per year system for win 8. There has been long time rummours that MS is working on system where you have to pay every year, so that you can keep on using windows os. (Subscribe system...)
Version 1 could alienate corporate customers for long time, version 2 could alianate home users... Either way it would be a risky task...