I'm pretty sure that WoW, while not overly taxing, is at the least moderately intensive connection-wise. I'm not sure what I would use to actually check something like that, and if anyone has any suggestions, I'd happily look into it.
All I know is, before the changes in the networking, I was averaging 26000ms, and now I'm averaging 800ms midday (yesterday only, can't really test until more people are back), and 50ms from 10:30pm-4am.
Oddly enough, I've always had more issues using online console games on campus, when PC games would work fine. I dunno, maybe it was the timing once again. I haven't really used my PS2 modem in a while.