Having been mentioned twice in the same thread, I thought I would stick my head in and offer a quick word.
First of all, at DPG, we are grateful for the cooperation that we've had behind the scenes from THG, Green Ronin, and Bastion Press. We are using both Freeport and Bluffside in our campaign setting, with the blessings of each of these publishers. I also have to say that Hal, Jim and Chris have helped point us in the right direction to getting our products to the market. Thanks guys! Also, Clark Peterson of Necromancer games has been extremely helpful on more than one occasion, and we will be doing some interlocking with some monsters from SSS and Green Ronin on a future product (also with permission). By the way, I am going to say that you can look for our first printed product in stores this fall, with many more closely on the heels of that one.
As for what we may see in the future, I wouldn't mind doing something with some OGC from a Bastion Press product or two, and I would actually love to do something more involved with SSS. What that may be, and if they would be interested doing an interlock project with us are questions that are completely unanswered (unproposed really) at this time.
As for something I would love to see - a multi part adventure produced by Necromancer games, Fiery Dragon, Green Ronin, THG, and MEG that may use Freeport and Bluffside as imporant adventure locations and monsters from Legions of Hell, Armies of the Abyss, and Nightmares and Dreams I & II. It would have to end up being a big ocean spanning Cthulhuesque sort of story that may reach high levels. Just a thought...