I'm also having the same issue from the topic, along with a very considerable fps drop, but only in the past 3-4 days, any time of the day and at any map. This is the first time this as happened so consistently but not the first time this game changes its performance so unexpectedly and overnight.
Ping stays constantly at +150 (the norm would be below 80) with several spikes to 300s and waaay beyond. I've contacted my ISP that informed me that everything is ok on their end and regular web browsing as not noticed any setbacks. Also played a couple hours at GW1 <3 with the ping at 40-50 and fps 80+.
This is very frustrating and completely denies the possibility of playing the actual game... Its stuff like this that make me consider going back to WOW....
