I'm not sure if you can use the media from it with other games you make with their other products - i remember something like that being asked before but i cant remember what the reply was XD
As for what you can do with it and darksdk - I suspect an awful lot less than what you can do with it and dbpro. The "programming" in fpsc is done with scripts you actually write in fpsc, what they are doing for dbp is releasing the source to fpsc which was written in dbpro itself. This would mean a HUGE amount of control suddenly given to users of both FPSC and dbp because they could modify the core engine and just recompile themselfs a new exe with all their new mods. However, surfice to say you wont be compiling any dbp code with c++ and darksdk. If you were uber brave and had a bit of time on your hands you could try porting the entire thing across!
I'm sure a few people would like that
But it wouldnt be a small job in any sense of the word.
Im also skeptical about these new commands added to dbp for the fpsc source because, unless im very much mistaken, im presuming them to be dlls lee wrote like any other 3rd party dll which would say to me they arnt coming to darksdk unless he also releases the source to them for us to modify and make into libs for our own projects. Or to call manually or somat.
Of course, take this with a grain of salt. I could be completly wrong about -everything-. FPSC could of been written in darksdk and the new commands are an integral part of the dbp engine rather than 3rd party dlls (even if the 3rd party dlls were written by the 1st party.. go figure
). These are my assumptions though, just wait for an official reply