I've been using metaballs in Houdini for 3-4 years for particles sim's... etc. but never for modeling. *shrugs* I hate the thought of having to model again procedurally in Houdini :(
That's what i call time traveling :) and actually this feature is pretty cool. But since people use other more natural sculpting methods it was abandoned i guess. This is also available in other applications. Houdini has such tool, cinema4d, max (although very crappy, blobMesh)... (i'm not sure about maya or xsi but…