Didn't see it posted yet, so here goes..
Luckily the company I work for has all servers (including samba as NT Domain controlers) on linux...read the article here
Technical and support fears are holding back enterprise adoption of Linux, according to AMR Research.
The analyst's Linux: Creeping into the Enterprise report suggested that companies perceive Linux as still not suited to mission-critical applications.
That makes us an early adopter. It does according to this article !!