Just doing a little research, I compared the new hallowed background spoiler from cenx with the marble section of the trailer. They are definitely different. I am concluding that at least 1 of a few things is true.
1. Purposed as alternatives to Hallowed/corruption are the Marble/Graphite respectively.
2. Based off of the design of the caverns (and a hunch) I believe it is possible that the Marble/Graphite are on different planets. (Planets being different from worlds. I am implying kind of a starboundish like feature but not as complex or fleshed-out.)
3. I'm entirely wrong about everything and thus deemed an idiot.
EDIT
Also while watching the Marble/Hagrid section of the trailer, I realized that alongside the white snow-looking blocks is dirt with skulls or something in it. This has a very different texture from normal dirt which supports the other planetary idea.
+In the goblin army shot, there is a golden bunny. (I might as well make a full trailer analysis instead of trying to cram everything in this one post)