Good point, but information you've used is not correct.
FY2008 Apple Unix Desktops revenue: $5.6 Bln.

Apple is fighting for PC/Windows desktops market share - they are not in traditional Unix market - big boxes for commercial workloads, mostly databases.

Are you kidding, right? Information from IDC WW Quarterly Server Tracker - CY2008 total Unix Servers factory revenue:
IBM: $6 387 mln.
HP: $4 561 mln.
Apple: $99 mln.

Sorry, but Apple can't be classified as "major unix competitor".