Think that NS5 will be the less-populated of the 2 worlds, even after all the testing / tweakign is done, and we roll out the full, official release? I pop'd back into ns4 (after a year + hiatus.. maybe popped in earlier then today, but i cant remember) and i was talking to people who JUST now discovered ns4, or people who dont even have the machines to run nwn2, or complained about how sucky nwn2 was, so they are sticking with nwn1 (and thus ns4) ect.
Granted that Ns3 still used nwn1, so the transition from 3 to 4 didnt require a whole new core game or more powerfull pc.. but still.. i would have thougt that more people would have gotten better pc's by now, and more could start playing ns5 with us early adapters
