I
started working on some but didn't get very far. My role in C3G & HoSS have taken up my testing energy.
Cavalier recently posted up a bunch of cards he has made so look up his thread too.
CobraVigon was making a ton of great G.I. Joe minis & cards too, I have not seen him post in a while though. Those are the two I'm most familiar with (follow the links) but I'm sure there are a few others out there. you just need to browse the custom threads or try to run a search.