In "the enterprise," Citrix still rules: At least where MS Terminal Services are used. However that may be changing in the future, especially with VMware's View PCoverIP virtualization. We're in the process of moving in that direction. We still have 120 terminal services servers, but we're moving our corporate HQ to a fully virtualized architecture to start, and possibly replace all 5500 or so workstations in the field as well.
Mark
I helped to setup my former company’s first VDI config on an HP BladeSystem and an OC48 MAN between a decentralized data center and 11 remote sites. We were hosting 12,500 workstations at one point.
VMWare is awesome stuff. I’m in a bad situation now, because despite heavy involvement and power usage of VMWare infrastructure, I don’t have any certifications, thus often keeping me out of the running for jobs. Being unemployed sucks. I don’t get to play with the big toys.
And Citrix rules in some areas, but VPN is more secure and much less of a hassle than remote desktop. I find terminal services to be painful now. I’d rather PuTTY into a Linux box or setup a site-to-site VPN for resource sharing and enterprise network use.