I'm holding off on buying the blu-rays of the films, because I fully expect them to get a fully-remastered re-release at some point, including the extended cut versions of TMP, TWOK and TUC.
Yes, this is certainly on the cards, but I'd say it's at least
another couple of years away - if not more. The current BD's are light years ahead of their present/antecedent home video rivals. They are comfortably the finest method of watching the movies at this point.
It all comes down to a question of how long you're prepared to wait I guess - personally, I've been enjoying these discs since release in 2009. YMMV of course, but I've always had an "enjoy it now" type outlook - fully aware of the transitory nature of home video formats! I would estimate Blu-ray Disc is minimally halfway into its lifecycle already!