We’ve been working on a new plug-in that provides image-based onion skinning tools in Maya. Here’s a video:
http://www.youtube.com/all_comments?v=fO1MyGUDYlI
We’re actively looking for beta testers right now–if you’re interested please email me at raf@anzovin.com. We hope that we’ll be able to release it late February or early March, for $29.
Unlike our other plug-ins, this one has been done entirely in Python, which means that we have one version that will work with any release of Maya post-2011 (possibly 2010 too but we haven’t tested that yet).
Hope you like it!
–Raf Anzovin
Edit: We have enough testers now. Thanks!