I also think one thing I have noticed is it seems like there isn't much anticipation for Season 4. Maybe it's the lack of news, or lack of Fathom saying anything about a theater event, but after the movie and now that we're getting out of that period, things are calming down.
I think it's natural, after the excitement of the novelty of the first season in HD, then season two with Q Who, Elementary Dear Data and the extended Measure of a Man, and of course Yesterday's Enterprise and BoBW in the third season, there are plenty of exciting hooks.
By the time you get to the fourth season, there isn't so much of a "hook" any more. It's almost routine by now to see TNG in HD. Season four also arguably lacks a big "event" episode. It's a great season, but I wouldn't say there's a massive draw. Redemption isn't half as effective as BoBW for example. It's probably my favourite season, with episodes like The Drumhead, Remember Me, Family, Brothers, Future Imperfect, Reunion, The Wounded, The Mind's Eye and Clues... but I don't know, it just lacks the absolute highs of season 3.
The excitement will gear up again when DS9 is announced. With that series I think there will be more continued interest, because with each season the show got bigger and bigger in terms of visual effects and scope. There are potentially a lot of things that will need to be newly remade with CGI too.