From, the most reliable Apple rumor site I've found (though it usually reports on, rather than breaks, very big rumor stories):

Apple reportedly seeks out Fortune 500 companies that have large installations of UNIX workstations and use high-end software like Cadence. In particular, Apple targets companies that have employees using both UNIX and Windows hardware. Apple seeds Mac hardware to these companies, making the pitch that by switching to the Mac, these companies could run both UNIX apps and regular Office-style software on a single box -- or even a laptop.

Very smart. :^)