Multiplayer is still easy in Dark Souls, just not organized mp. It's a pain in the ass to go up against or with specific people, but I've never had problems invading in various ways or assisting people. It is quite a bit more complicated, though, since there isn't just red and blue phantoms.
And honestly, multiplayer in Demon's Souls was marred by the fact that everyone just wore light armor and roll/grass spammed. You can't tell me that was fun.