When I stared with .Net I'd say I had intermediate
VB skills and advanced/expert VBScript skills. It didn't take long at all to get into
VB.Net as there's not all that much that's not supported from the old versions. That being said, there are loads of better ways to do things in
VB.Net so it's just a matter of learning those.
I've now been doing .Net for over a year, and I'm no expert, but I have learned a ton and would say that I'm probably up to intermediate level (4 on a 1 to 10 scale).
Once you get rolling with .Net, you'll find it much faster to build things than it was in
VB/Script. If you have VS.Net it's much much better. I never did .Net outside of VS.Net. That's how I learned much of the syntax, by discovering things through intellisense. Also, take a look around a Namespace browser and you'll find things that are very useful.
I think all-in-all, you don't loose much by switching while the gains can come very quickly.
Peter