Even if blu-rays, aren't in DS9's future, I do hope they do remaster them for streaming/syndication. It'll be a shame not to get all those wonderful special features that the blu-ray releases offered, but I can live without them.
Actually studios are finally beginning to examine that and are offering "special features" as part of their streaming packages, so I suspect that will be part of the strategy.
What's really interesting is waaaaaaaayyyy back in 2007 during the Format Wars Microsoft and Toshiba were working on new streaming technology which would essentially stream the complete image of an HD-DVD including menus and bonus features... it would have essentially been a disc on demand.
I think we will finally get there in the years ahead.