1. yes, agp is dying, and probably the new AMD socket M2 that is coming out next year wont have agp. but, maybe a few mobo makers will do it, but its really unlikely. especially since they dont make s939 agp boards any more.
2. ddr is already replaced by ddr2 in intel platforms, and ddr will be replaced by ddr2 in the M2 socket. but 939 mobos will be made for a while, well into next year.