The subject that everyone seems to talk about is virtualization—putting all of your servers in a virtual environment, which is hosted on 'big iron'-an, extremely stable server, or consolidating services that are provided by several servers in a branch office into a virtual environment. It also might not involve only one server, but several servers that host several virtual servers that each provide dedicated key services. Quite a few companies virtualize their DCs nowadays, and some of them have their entire AD infrastructure running on Virtual DCs. The reasons for doing so are valid, especially for smaller AD environments, and if you have the possibility it might be a good idea. However, it has to be said that this also needs to be evaluated for each organization. If the DC load is quite high, as it is normal in very large AD environments, then it would not be wise to virtualize the DCs since they will start fighting with other virtual machines for resources...