I have spoken at length with wersi at various times and their story is the windows operating system is completely stripped down with non-applicable sections taken out - this has been done since win98 so there is nothing particularly new here.
A keyboard with cubase or sonar built in like the abacus would be an interesting concept, even though I remain doubtful at the present time over the stability, even though XP (SP1+) is probably the best windows yet.
Much more important, having used hard drive streaming sample generators they would open up a whole new ball game in sound quality, albeit at a price. You only need to listem to B4, FM7 etc for half a second to see that.
The reason MACS are so stable (but ask the people who moved to 10 early!) is that the peripherals and software is limited and therefore easy to debug fully in relatively fast time. The reason windows is less stable, apart from the laziness and incompetance of microsoft, is that there is a huge range of hardware/software to load in and interact with each other and windows to cause conflicts.