in my point of view crossfire is windows only.
and another fact: the most linux users i know spend more money on hardware than windows users.
for example i know a lot windows XP-32bit users they do not have need for more than 4gb ram. but ram only cost 4€ per 1gb and linux users trent to have 16gb ram and more.
also windows users (gamers) buy an FX4170 (4,2ghz) because single threated speed
most linux users buy 8core-16core and more cores.
Linux users are completely computer addicted nerds/geeks.
this means: no they don't care about money.