perhaps many "enterprises" are realizing that that many efforts are working against each other resulting in lower efficiency and higher cost. One section fights to create the well oiled machine for anything from mail filtering and exchange to ldap services while another team is dictating various "features" (read: chrome) that not only bog down the enterprise but cause stability and security problems. Instead of those chrome demanders merely saying they wanted certain types of functionality they demaned specific implementation for no other reason than zealotry.
I've worked in areas that had all the latest and most expensive equipment from Sun and HP only to have them configured in a manner that is akin to using Ferrari's to haul tractor trailers and the rigs racing at the track.
Many places (not just the government) randomly throw money at IT, not understanding what they want from IT or what IT can do (yet dictating specifics ironically). Some have decided this is foolish to spend so much money on expensive "enterprise" equipment when you can more cheaply use PC's (including multi-proc) with server farms. Eventually, I am betting the 64 bit procs from Intel and AMD will overtake all but the highest end (and highest dollar) specialized server from other vendors. The bus architectures, memory and add on components will much better be able to work in distributed environments, whether clusters, grids or simple fail over server farms.
As for what Unix used to stand for... consider this, it was once said that the fundamental idea behind Unix software was that you had many small components that did one thing and did it WELL. Many in the Linux community have forgotten this and make clusters (as in cluster fsck) of inter competing components that don't allow for a clean modular extension or substitution of certain components to give you the functionality you need.
In essence, they have turned Linux into a harder to use MS Windows.