There isn't a public release date quite yet. Last week we resumed working on the real spaced project after a hiatus to complete the Steinway. We'll almost certainly use our own engine since it's been completed and already in use in the piano. We haven't made any decisions on whether the impulses will be also usable by altiverb /IR1/etc though. Hope this helps-
But will "Real Spaces" be a stand alone product, or it will be integrated in GOS2 or GPOA?
I think the way to go is to have 2 versions (or more) like with the steinway. One version with the convo software and the IR's and another with just the IR collection in WAV/AIFF format (maybe even a reduced set of impulses, like 4 or 5 stage positions from just one seat position (the director's one, of course!)