Michael,
Just as a follow-up...as Bonnie pointed out, quite a bit of it is personal preference. Since you said you've been working with .NET for awhile, you obviously know that the big learning curve is the framework.
Some people use VB.NET for user interface work and C# for non-visual classes. I use C# for most things and am not fully convinced that using VB.NET for UI work is significantly better, though there are signs that the next version of .NET will offer more productivity tools for VB.NET.
The one area where VB.NET is much easier is Office Automation.
Kevin