Now, being Microsoft, they will probably not take HTTP out of IIS (or IE) but add all sorts of bells and whistles to this new protocol to do things they either can't do or can't be bothered doing via HTTP.
Right. Think Kerberos. Okay that one seems to have since become moot, but add the DMCA and -- if/when it passes -- the SSSCA and the tweaks they add to HTTP "for security"[1] will be legally unavoidable.
[1] It would be too obvious to point out that there already is a more secure protocol, called (surprisingly) HTTPS, and that any changes Microsoft might make to HTTP should then be called HTTPMS, but that's just a marketing issue.