Similar to @Tanner's experience, I have lived in a Windows/Linux shop before (most desktops Windows based, all servers linux-based). We had some killer DevOps guys, but they went through a lot of headaches with Samba. They ended up settling on Isilon (I believe that's the right link), which had its own share of learning pains.
The pain Tanner mentioned is similar to what we experienced on both Samba and Isilon. The final state we got to, though, was really nice.
- Windows users mapped to Linux users, so the file system always saw you as the same userid (file ownership was always by linux-cole, and never my windows counterpart)
- Password resetting was seamless
- Could edit files interactively from either system
I think Isilon is definitely geared towards scaling hardware in a virtual environment, but I would expect there are other solutions out there. I second the recommendation to move as much as possible to Linux, and use Mac Desktops as a fall-back before landing in Windows land. But then again, I am quite biased on that front 