We will all have at least one game that will probably never leave Windows(or OSX), either due to age, publisher ect....
I will probably just run Windows on a VM at that point, or give it a separate HDD to itself, and then use link to stream. That is unless WINE or Gallium manage to properly integrated DX11 support, in which case significantly less games would require a windows partition.
Of course if I ever want to game on a TV the link would also save me the trouble of running an HDMI cable or building a separate HTPC regardless of the OS I game on.