It's been 360 days since HMX has done anything that relates to TB:RB (Rubber Soul album release). Since then, the most it's been referenced is to say it will not be exported to RB3.
With it's wide gap of absolutely no press release announcing the game's future, many people believe the game is dead. If HMX really cared any more, they would have given us something by now.
Well, if you remember those days, when RB:Unplugged was forgotten and discontinued DLC, they made a pretty direct statement that was pretty close to their most recent DLC release.
This is how I see the game's future:
HMX realizes that Beatles DLC is "very highly" requested. If they were never going to release any more DLC and they knew it, they would have made an announcement way long ago.
Maybe we will never get any more DLC, but it might not be HMX's fault; it might be Apple Corps's. HMX might be in tight negotiations on which songs they could use, but I'm sure Apple is strict on which songs they want floating around on a video game. They're floating on a bunch of other negotiations as well (recent addition to iTunes).
So, while we all go tugging on all the forum mods to go get us more DLC, they might possibly be in the UK talking to a represenative who might be offering to give us the full Revolver album.