Enter Wersi OAS, which in its latest version (OAS 7) makes the computer almost totally invisible to the user.
Each version of OAS gets rid of more and more of the computer, and the next version will probably banish the computer from the user completely. (This last statement is an educated guess, I have no inside knowledge)
The future certainly looks bright.

Lionstracs
You are correct about the Jack system for the Mac and Linux, which gives a lot more flexibility then Windows, however as the Jack system is also under development for Windows, the advantage may not be there for much longer. (Vista also has more advanced Audio drivers, even though in its current form the rest of the OS is a bit of a disaster)
We will have to wait and see what the future brings

Bill