What I'd like to see is a broadcast-type event. Say at a random, changing, time window every two weeks, there's a message in whatever mission/story/raid/match/orbit you're doing. Comes across the screen at the bottom like the "contact destiny servers" message...you press square to open the message and it's a recording from rahool or cayde or eris or arach, etc., saying that the tower has been attacked by X forces. Cabal incursion, Hive infestation, Fallen ketch... Giving everyone the option to immediately jump to the tower (or to bannerfall, maybe?) and defeat a heavy wave of attackers and a few ultra bosses, with a fireteam and whatever guardians also appear in your session. Only playable once per character each time it happens, and completing it gives you one faction level with whoever sent the message. Or some other high-light legendaries and exotics. Maybe something special from the speaker for defending the tower. This could even be done at places other than the tower. A broadcast saying there's an attack in the cosmodrome, or the reef, or any other place. With so many enemies, and full sessions of 12 guardians battling back...that'd be great.