Assuming this game comes in a retail disc as well as they won't release anymore DLCs, this is basically the original game plus current and future (awakening) DLC's? or what I just said and it slightly modifies the original game.

No it's a being released for $40(?) but isn't the original, you'll need to have that to play it.
It expands upon the orignal, so you complete the original then you play this. It's kind of like a sequel, but they're often not as long, hence the cheaper price.
 
They were right on the bombcast about people not getting expansion packs.

has it been that long? I remember expansion packs working this way lol