Impressive, but I have to wonder how many compromises had to be made, and advancements abandoned, to keep apps like Reversi and Dosshell all the way up through Win7...
You may be interested in this technet article on the concept of Shims http://technet.microsoft.com/en-us/library/dd837644(WS.10).a...
Not only can you make your own, Windows ships shims with each release to provide compatibility support with popular user applications.
Edit: fixed some grammar.
It took me some years to internalize the benefits of "if it works, don't touch it", and I currently apply to a lot of home maintenance problems, which are outside my area of expertise.
I think it's one of those decisions where no matter what choice is made someone will complain about it.