Some of our clients use Windows Server (in our case, Server 2008r2) as a terminal server. This has many advantages in allowing them to consolodate their usage in one location.
At a certain level, it is more cost effective. The workstations can be anything laying around, and we don't care how reliable they are. Many of these clients simply purchase a used workstation, then make a Remote Desktop (RDP) connection to it. The operating system does not matter much, so long as there is a viable RDP client available on it. Currently, our clients use Mac OSX, Linux, and of course, various types of Windows. If a workstation dies, simply get another one and make the Remote Desktop connection again; your printers, applications and data are all still there. Unix has had this functionality for a long time, but Microsoft realized the need as far back as Windows Server 2003 and our clients have benefited from it.
In our case, we created the servers as Xen Virtual machines. Two of these have gone through at least two pieces of hardware by simply copying the virtual image to a new physical machine, and they work very well.
Warning: I'm not sure why, but a Windows Terminal Server can not be on the same installation as a Windows Domain Controller. In that case, you need two installations.
There are some issues involved with doing this. This category in the Knowledge Base explores issues, and their resolution.