The PS4 has a much larger player base and superior hardware, but I would wait to buy anything, however. The great majority of games for either system are awful. Killzone sucks, Ryse sucks, Dead Rising 3 is OK at best. The only truly great game released for either system is The Last of Us, and you can play that on the PS3. As far as multi-platform games go, almost everything will run smoother and with better resolution on the PS4.
You should really give up your console peasantry and join the PC master race, though.