Pre-order trailer: unknow block!

[Soprah]

http://www.youtube.com/watch?v=WvYzmBjhX6U

Just have visited this awesome trailer one more time.. And i could discern a bloc at 0:31 that I've never seen before!
It is grey, looks like steel, with a smart gap to look through.
has that block ever been released?

It just looks great!

[TMarc]

The unknown block is a running gag of Nadeo, as they do this with every release
In fact they have much more blocks internally than they will ever present, because they are trying and evaluationg which blocks are really required and make the most sense for best gameplay