Again, the skills the employer wants to hear are usually listed in the posted job description. If you have demonstrated the skills listed and can back it up with examples then these are the skills you will want to talk about. Skills you have used or can show you have demonstrated in previous job assignments.
I forgot to review my VB6 for this job... I think the answer was "DLL mess". But it's been so long since I looked at the differences between VB6 and VB.NET... I forgot that "trivially obvious" answer. Of course, the fact that it was an interview question tells you this company has a lot of ollllllddddd code.