I'm not entirely sure if you fully grok the concept of the Windows Scripting Host.
The idea is that when any program uses the WSH for it's scripting, any WSH compatible language can be used. Take dIRC, a simple IRC client which uses the WSH. You can use any language to program it, even ones released after the program was released. People can chose to code in whatever language the like, be it from ObjectRexx to TCL.