Not exactly. Metro and its app store are only "half" of Windows 8. The other half isn't sandboxed in the walled garden style. To put it another way, Microsoft isn't building the Windows App Store on the back of existing software, but from the ground up using only sandboxed apps.
Microsoft isn't likely to create the sort of moving target for developers that Apple has recently because doing so would not be consistent with the B2B model that underpins their corporate culture.
Metro is a future of Windows, just as Server Console mode is (though admittedly on a potentially different scale).
The parent said "going the same way". It seems pretty obvious to me that they are deprecating the desktop and Windows 8 is just step 1 of that.
I don't see Microsoft going that way because they give a shit about software developers.
But sandboxing cripples, besides our ideals and personal experience, the apps we make. Users (of powerful, hard-to-sandbox apps) will suffer from this. Those users far outnumber the developers, and have great market significance.
Granted it's a big change from earlier times, the strategy of sandboxing works really well for security and general OS integrity (as iOS has proved) in a world that has no patience for fragmented and exploitative software. Perhaps we lose a little something in the process, but it's in the service of a better overall integrated service and experience.
Oh and by the way: Microsoft is going the same way too with Metro.