How and why are users going to convert to something different? Well, that's not really the issue. Look, if someone is currently using DBFs and wants to stay with them, that's fine.
My point was (and is), that on a new project, I would not chose VFP tables as my backend DB, even for a small app. I'd use sql express. I used it twice last year and was happy with it. I'm disappointed with the provider for VFP, and I miss out on the t-sql '05 constructs that yield additional productivity.
The counter-arguments are not lost on me (low hardware rqmts that preclude things like the .NET framework and sql express), difficulty in gaining access to client system to troubleshoot, etc.) They are valid arguments. But I try to avoid such work. I have two clients who are what you might describe as 'mom and pop', but there's a general baseline environment that I expect.