When FOTR was being made, PJ already announced there won't be Scouring of the Shire, along with the removal of Tom Bombadil.
Unless they change their minds and got the cast to reconvene and shoot brand new footage for Scouring, I don't think we will be seeing that in the EE DVD of ROTK, as much as I'd like to see it. I personally enjoyed that part of the book, and it sure beats the evil eyes the hobbit heroes got upon returning home in the movie version.