It obviously learned a lesson from the malware distribution center that took over much of Google's Android App Store at one point.
It's not Microsoft's first effort to get a look inside its customers' hard drives.
The spyware-ish Windows Genuine Advantage was a revolutionarily intrusive measure when it was first introduced in 2006 to verify Windows licenses before allowing customers to download Service Packs and other important updates).
One analyst quoted by Computerworld thinks Microsoft's process of filtering and monitoring apps in the Windows Store will be rigorous enough to keep out most of the malware and that it will follow accepted procedures to shut off or uninstall apps from the hard drives of customers.
I would hope that's true.
The Terms Microsoft has posted right now don't require that, however, so it would be free to do as it likes.
Even if Microsoft handles that power responsibly, allowing it sets a precedent that will have every other software vendor building in kill switches, PC-inventory tools, license-monitoring and verification services and half a dozen other types of proper-sounding but still intrusive commercial spyware.
Even assuming Microsoft does responsibly use the power to rummage around the hard drive of customers at will, the ability would present an awful temptation to use it to find out what competing products a customer is running, to "optimize" Windows apps or services by shutting down those of other vendors, or just monitor customer PCs to make sure they don't load any Microsoft products illegally.
Microsoft is always quick to justify any such intrusion as a way to prevent piracy, preserve its copyright and collect anonymous usage data to help its products run more effectively. It runs report-back functions in Microsoft Security Essentials, Office, Windows XP, Vista and 7, all of which are designed tor report errors and regular usage statistics. It's possible, though often awkward, to opt out of these, though most go back on by default after some patches or updates or when some random corruption forces the user to reinstall the whole app or suite.
Still, while I'm sure we all appreciate the priority Microsoft puts on making its products run effectively, it doesn’t seem as if it's the responsibility of the customer to let a vendor spy on every little thing he or she does simply to make sure one set of programs or subroutines doesn't conflict with another.
From most vendors that intrusion would seem creepy and presumptuous. From Microsoft it seems like a demand for fealty and submission to its priorities for your computer.