We are starting to use Linux at my company. IT has said they will support it, they have a bunch of firmware developers on Linux workstations, our FPGA designers look like they will be first to start using Linux heavily with the new Xilinx ISE 6 and Synplicity. Our ASIC designers are starting to take some interest in it.
I don't see the company replacing all workstations with Linux ones ever. I think we are too much in love with MS. I do almost everything in Linux, even looking at managers' powerpoint and excel documents with open office. The one thing I can't do in Linux is the outlook shared calendar stuff. I VNC over to an old pitiful windows machine for that.