I live in Hampton Roads, VA and have FIOS with the same issues. It started after the server patch and hasn't stopped. It worse in duty finder and fates. So far I have been able to clear some dungeons because I compensated for the freeze lag by continuing my rotation even with the freeze.

I lost the easy Lvl 30 THM quest because of the freeze and lag spike. When that happen it was only freezing when I would go to instance fights. Now it will do it random in the world also while doing fates and quest/leve mobs,.

I have a Verizons second tier speed and doing the speed test everything is fine and anything else I play or stream works just fine. BF3, Guild Wars 2 and any of my steam games work just fine online. So I know it's not the ISP that's the issue. I even used my ASrock utility program to open up the bandwidth for this game and it didn't help.