Looking around the internet, I think Chris123NT was the first to discover it, since all the links of the Windows websites eventually lead to an entry on his blog in which he details the process. Windows 7 still installs Internet Explorer 8 by default, but you can remove it via the "Turn Windows Features On or Off" feature.
Currently, it removes all references to Internet Explorer from the operating system, while also deleting iexplore.exe. It leaves all other files intact, which most likely has something to do with the fact that other parts of the operating system rely on Trident, Internet Explorer's rendering engine. You can't really delete WebKit from Mac OS X either.
It's a step in the right direction, even though I hope that to squash all doubt, Microsoft will explain this change in more detail.