I've never tried to run a .net app under wine. I use it (via Cedega) to run a couple of windows games I like. I use native Linux apps for everything else.
On the rare occasion I really need windows, I have a VM I run.
What VM do you use, and on what Linux?
We went to Redhat recently, b/c Oracle will support the OS. We'd been having a lot of OS-related problems with Oracle on W2KServer. And, of course, we're all partial to *nix.
But, we've got some .NET apps that I'd rather not have to port, and at least some of them I want to run local to the DB