Hey guys, look at what I discovered whole browsing the Dakka forums:
http://www.dakkadakka.com/Default.aspx?tab...3703&view=topic
Apparently, they're a new Guard regiment called the Vostroyans. They will be part of an upcoming book called Codex: Cities of Death, and will feature in some sort of WW campaign this summer.

But that aside, don't those models look fantastic?

They look pretty cool like a british colonial/ star wars person but yeah they look cool.... :D