I honestly don't see this as a homage to anyone. It looks to be a completely new character. The only thing resembling War Within Grimlock is the pipes coming out of the shoulder - Take that out and he doesn't really resemble any existing character.

This looks very good but I need to see colored pics. It also looks like in these promo pics, the waist is mistransformed. The pictures shown at Botcon had the waist secured in place.