This was slated as Q2 2011 but nothing's on the radar. Any info on when it might be released?

Not from what I can tell.

I'd assume after Citadel of Skulls, if FFG is follows the pattern for the release of The Frozen Reaches and Battlefleet Koronus. Amazon has it currently listed for July 12th, but I highly doubt that date is correct.

havn`t got a clue when its coming but cant wait for it`s arival (more info and the shade side of life yes please)

on that same line cant wait for the DH aribitors and scum book or should that be lawbringers and law breakers? oh well whatever it is cant come too soon for me

Well, the book is definitely some time away as of yet - it's not even featured in the Upcoming section and it wasn't yet officially announced on the main FFG site. After such an announcement is made you can expect the book 6-8 weeks from that time. So I would say end of August...

As a sidenote: I've just skimmed the free intro adventure for Black Crusade and apperantly Sam Stewart is the lead developer of that RPG (as well as of Rogue Trader too) - so that might explain why RT supplements are "late" compared to the release scheduele. Just a theory though.