Should probably compile a wiki collection of this sort of resource at some point…
300mb of model goodness!
http://mikepan.homeip.net/blog/blender-source-file-pack/
Momoko's used these in some of the jME3 demos… They looks pretty good and are released as "do whatever you want with them"
http://otothecleaner.free.fr/downloads/downloads.html
http://www.jmonkeyengine.com/wiki/doku.php?id=resources
This is a compilation of various useful (usually free) resources for use in jME. These sites could be added there.