Jim,
In 2 years (early fall of '06), we'll be looking at the next generation of .NET, Whidbey. A significant upgrade? absolutely. But still .NET. I'm working with a client who is going through a major re-write from Fox to .NET, and they're also keeping an eye on the next set of tools. The two are not mutually exclusive - they are part of MS' general direction. And this was a decision they reached internally.
VFP isn't the only development tool that works well. .NET works well in production. I've got 4 apps in production, and working on #5. No, it's not perfect, I've got gripes with it and I'm honest enough to admit it. VFP isn't perfect either.
To answer your specific question at the end, a transition plan is almost always in order. Because most Fox->.NET projects take 6-12 months, the Fox apps will always need to be maintained/tweaked by one team while the app is being re-tooled in another. The Fox apps won't disappear overnight.
Your argument is a common tactic to persuade people to stay with the status quo and avoid .NET. It's more like the politics of evasion. But why has that argument never been made about Fox? If you follow the argument consistently ('hold on to what's stable'), then why did so many go from FPW to VFP? And then to VFP5/6? And then 7/8? And then get all excited about 9?
Are people permitted to get stoked about new technology, only if it carries the Fox logo?
Kevin