I am currently looking again into texture splatting.
As far as i can see there are at least three solutions:
BlackBluegLs one here
hevees one here
and renanse has one which was not committed (and wont be committed ?) to cvs
I would propose to take one of the solutions (or merge the two into a new one) and include that into cvs if performance is ok.
BTW, after seeing that somebody might actually want to use my code, I fixed a problem with some NVidia cards and my glsl code today, and created a working webstart demo 
goto http://www.jmonkeyengine.com/jmeforum/index.php?topic=4146.msg40211#msg40211
the shader is in user-code. Test-class is not ready, sry…
i have currently a problem with the shader and other textured objects without shader. all other object are black or culled. ://
Is there a chance that one of the 2 solutions gets into cvs this week and will be the standard of jme? I dont care if its still a bit buggy. Otherwise i had either to choose between the 2 solution or start writing my own