Well, this is both good... and bad.
One of the strengths of an "open" platform like Windows and DOS, was that the end-user was ultimately in control, of what programs that they wanted to run. Including, unfortunately, malicious ones.
If MS "locks down the platform" (as they've been trying to do, a-la XBox!), then users lose that ability.
Under the banner of "security!", MS is going to "close the platform", "close the loophole", whathaveyou, until our "Windows"-alike boxes, will ONLY RUN "approved" applications, all others (conveniently, open-source / free-software as well) will be DENIED.
Edit: I used the term "Windows"-alike, meaning, it will have the familiar UI of Windows, but at it's core, it WILL NOT BE "Windows" as we've known it, the open platform that allows the user to run ANY code they like on it.
Call it "WINDOWS LOCKDOWN", or "WINDOWS PRISON", whatever floats your boat. The "software Panopticon" is real, folks, and we're watching it take hold, first-hand.