It'll change. Late last night I (WH) was with a BW and two RP (admittedly not the ideal setup) wandering around, and we had loads of clashes with small groups - lots more fun than zerging, and once people start getting bored of it, there should be lots more small group RvR to be found.
Indeed it will, Daocs early days was all zerging, took a while for people to get out of the habit, but they did eventually and then things were a lot more strategic.