So after many people contributed real money to pay Qarl Fizz to implement the mesh deformer, and after years of, well, something, LL has decided not to support it. instead, they will support something like the "Liquid Mesh" (which was controversial because it took advantage of SL's actual behavior as opposed to its specified behavior). "Bones" will be added for body parts that in RL don't have bones so that those body parts can influence the position and motion of mesh clothing.
I am not a builder or virtual tailor, so I cannot have an informed opinion about which method is better. If I understand rightly, though, the mesh deformer would "just work": you make a piece of clothing to fit the stock avatar at whatever is considered the default slider settings, and the deformer would take care of making the clothing fit its user at whatever slider setting he or she has in effect. The mesh deformer, therefore, would at least seem to be easier from the clothes-maker's point of view.
One thing I think we can say: what sane person will now do anything to try to improve Second Life, in view of what has happened with the mesh deforrmer? IMHO this shows that the "shared experience" clause is every bit as destructive as we thought it would be.
P.S. In this regard, two must-read blog posts: