Microsoft is moving in on Citrix territory even more as they now introduce the following components: Terminal Server Gateway, RemoteApp, and Terminal Services Web Access. Terminal Server Gateway allows remote user's access to Terminal Servers through your perimeter firewall. RemoteApp allows you to publish applications on a Terminal Server as opposed to an entire desktop. Finally, Terminal Server Web access provides you with a portal to access application and/or desktops.
I know many clients that have completely moved away from Citrix to save on license costs due to the fact that Terminal Services offers such a robust amount of functionality. Once my labs are complete I will upload some tutorials on Terminal Services in action.