Is anyone surprised? As soon as anti-spyware apps became popular, a market opened and Microsoft exploit markets. Even if they never charge for this tool they can use its addition to sell Windows, or to deflect the criticism that they aren't doing enough to tackle spyware that may be reducing sales. It's good sales acumen. And users will appreciate it.
As experience shows though, third party is almost always better than Microsoft offerings, no matter who they licence/rip them from.
