After I finish in academia, I'm planning on spending a few months of my newfound freedom to create a 100% VB6-compatible language add-in for Visual Studio.
....then sell it back to Microsoft
The funny thing is, unless you use Declare Lib to do funny stuff with Win32, it should be possible to use WPF as a UI layer for VB6.
You can do it now, with some hacks. Make a .NET DLL project, create your WPF controls, create a WinForms control with an ElementHost on it, and then expose that winforms control to COM. VB6 picks it up and you can use WPF inside of a VB6 form.
How do I know this? Because my company has tons of VB6 software that they have no interest in rewriting.