I think it's on this site somewhere but…if and when will Jmonkey support shadows :D?
Thanks
Grab a copy from CVS, and feast your eyes on jmetest.renderer.ShadowPass or look at Lesson 9 of the FlagRush tutorials in the wiki (also in CVS: jmetest.flagrushtut.lesson9.Lesson9)
An alternate answer could be: upcoming 0.10 release