Since you mention testing, I thought I should at least mention NAnt. I run a number of build servers under CruiseControl.Net that makes calls to NAnt. The NAnt scripts make calls to thing like NUnit, MSBuild, devenv and FxCop. This automates our continuous integration and release builds. There are other tools that can be thrown in like NCover. I also do automated Flex builds, but that is under Hudson. This is on Windows Server 2003 and 2008 in 32 and 64 bit versions.
As others have mentioned, PowerShell is very helpful as a replacement for your other scripting tools. Personally, I still use Perl.