Campaign settings are a major investment - and a risk. They don't sell in large numbers, and they require committed support by the publisher. You therefore have to get it right and be confident that the setting will sell enough for you to be able to support it - and that you have the right support framework in place.
From the RQ6 point of view, we have two in the direct pipeline. 'Shores of Korantia' is a setting and campaign book, the sequel to 'Age of Treason', and will be released early 2014. Its finished editing and is in art and layout.
We also have Glorantha, with our 'Adventures in Glorantha' being written for RQ, with a campaign book to follow very soon after. Also for 2014 will be Mythic Britain, which I'm writing at the moment, and 'Luther Arkwright', which is Moorcockian, Plane-Hopping, Comic Book, Existentialist, Steam Punk Pulp adventure.
This weekend RQ6's boards mention a new, or at least re-published, setting - Empires Rising. Core book, adventures and a campaign in the pipeline, which perhaps addresses the issue Olaus Petrus brought up. The wheels are turning. Probably. It's hard to tell with the naked eye.
This is actually being published by Nathan Baron's 'Lion & Eagle Press' under the RQ Gateway license, so its not a Design Mechanism product. There is also another RQ Gateway license setting book, from another publisher, waiting in the wings while we get the press release details together. And its a lot different to the others already mentioned.