It's long overdue, given Battlestar Galactica and (later) Stargate have been out in HD for years.
I wonder if they'll create any special new extra features? In-universe ones, besides slightly more candid behind the scenes docs. Like a guide to ENT-era starships with animated CG walkthroughs and perhaps some way of illustrating pre-Federation history, the show basically got cut short right in the middle of? Whether that's what played out in the Pocket Books novels or some other road map of ideas, the new showrunner(s) had planned to cover.
Maybe some alternative title sequence music to opt in or out of, using seamless branching.
I imagine a Blu ray set will probably be timed to coincide with the new film. Seems like an obvious marketing strategy to take.