Love it or hate it, the new "majority market" is
the mixed Windows/Linux shop.
Linux isn't even a blip on the radar in the vast majority of shops. Having one
in the building isn't the same as having a mixed shop.
Until and unless the same variety and number of applications are available on
Linux as on Windows, with the same or better user interface, Linux and all other
flavors of UNIX will remain marginal outside the realm of servers.
I've never understood the attraction of Linux specifically, anyway. Why not
just run FreeBSD or something?