If it turns out to be a typical PC-gaming style "expansion pack" it will be. In the PC world, expansion packs don't work like they seem to do with console games where you get a few new maps, a couple of trinkets then they pat you on your head and send you on your way. True expansion packs add on to the ENTIRE GAME. For example. Blizzard released an expansion pack for Diablo 3 earlier this year---The Reaper of Souls. You practitcally got a new game. They completely redid the loot system. They added on an entire new (fifth) chapter to the campaign. And added an entirely new mode of play. PLUS a brand new character class. When the original game was released in 2012 it got sort of lukewarm reviews. But the expansion pack got rave reviews. From what Bungie has said publicly, they seem to have something similar in mind for Destiny's expansion packs.