His response (bold emphasis is mine):
It's hard to say. I don't know. Batch files and the programming that is going on in those definitely need some help! Another language that is difficult to learn, but very powerful, is XSLT.
I see lots of little languages go by in various projects and I tend to stress internally at Microsoft that we all need to get on the .NET Framework so that we all share the same power of the API, regardless of our language choices.
One of the trends I think is interesting is the integration that is happening with programming models like ASP and XAML, which are mixtures of declarative and programming code that give you an amalgam of two different programming disciplines.
What I'm shooting for with the next generation of Microsoft platforms is to use XML for declarative tasks and C# for programming tasks. I'm less of a believer in using XML to "new up" objects in C#.
I'd still love to hear his thoughts on Windows Workflow Foundation in particular...