I got e-mail from an interested party pointing me to Martin Fowler's description of the PresentationModel pattern.  Written up just last year, I hadn't seen it in the literature before.  I've got to read it a couple of times and think about the subtleties, but it is very close to the basic Model/View/AbstractView version of Model/View/ViewModel I mentioned.  Fowler even speculates on whether .NET data binding could take advantage of the pattern...

As usual with Fowler's stuff, well worth the read, especially for his compare/contrast with MVC and other patterns.