Seeing as Metro/Win8 is MS last desperate push to enter the market for tablets that in the near future will replace the market where they currently hold almost all their monopolies (the desktop), that's a very accurate description of what will most likely happen.
And seeing as Windows is not and never was an OS for power users, they will lose the remaining desktop niche - which will be populated by exactly those power users - as well once the tablet will be our primary multimedia communication device.
A lot of Windows users do consider themselves power users even if they have minimal knowledge of other platforms. For example, it's quite frustrating to participate in PC building or gaming communities where every schmo thinks they're an authority on computing.
I think this too will fade with time as gaming moves to the tablet/other platforms. My prognosis is that the only people using desktop machines in the future will be scientists, professions performing heavy computing and programmers/developers.
And seeing as Windows is not and never was an OS for power users, they will lose the remaining desktop niche - which will be populated by exactly those power users - as well once the tablet will be our primary multimedia communication device.