Softgrid and Terminal Servers
In Terminal Server/Citrix Environments we see a lot of over capacity of the server estate. Specifically when a business has one troublesome application that has incompatibilities with others that already are in place on the server farm.
You have all probably seen the below where we show a basic over view 
off applications conflicting;
Application 'A' and Application 'B' may need to do a number of valid tasks but may conflict or overnight certain registry keys, ini files, or have a conflicting dll.
Overall it leads to increased TCO which spirals your support costs for what seems a very simple application.
Because Softgrid uses a process of virtualizing these core components it can lead to fewer application conflicts and help increase the capacity/utilisation of the Terminal Server Farm.
Softgrids 'SystemGuard' is what prevents applications from conflicting and talking with each other. The systemguard is implemented on the each host machine with a small client. The Client then captures requests intended for the Host Operating System and Redirects them to the either the Virtual File System (VFS) or Virtual Registry (VR). When the application does not find what it requires in the System Guard, then the request can fall down to the host Operating System. However Read Only access is given to all these requests that fall down to the underlying OS configurations.
Personal Data, Such as the users profile is left to continue as normal, and basic tasks and systems services have read and right access also.
So why is this good for Terminal Servers?
Like we Said in our example above, Application 'A' and Application 'B' may have had a number of fundamental problems that could not be resolved due to dll hell or other limitation. Softgrid allows us to help separate these applications whilst keeping our estate functional.
In the example below, I have two servers. The Applications use to be separated on different servers.
One Runs Microsoft Access 97 (Because so many companies still do!) and the Microsoft Access 2003. Before I would have had to increase my server farm to manage this environment and give me the stability I need in the enterprise, however now with virtualization we are looking to collapse these barriers.
Application Silo and now ...... 
Server Consolidation (Less Network Ports, Less Power/Electricity Consumption, Less Management)
There was a great web cast by Alex B and Chad J. I think that you should at least have a watch and suck all the info in!!!! Its all great stuff!