Strange how this whole argument seems like a step-by-step repetition of "GUI vs. command-line", a quarter of a century ago.

On one side, we have the beautiful new Apple system with no backwards compatibility. On the other side, there's the "industry standard" provider who has announced plans to extend their existing system with a cool new interaction layer while retaining full compatibility. (In 1986, this role was played by IBM with OS/2, but the GUI software was Microsoft's.)

Gruber even mentions DOS drive letters as an ugly wart of compatibility. This same argument could have been made in support of the Mac back then...

These fundamentally aesthetic points seem pretty weak in face of the appeal of backwards compatibility. If Windows 8 can make the "convertible tablet" finally work, it will sell.