I've had terrible lag today, but I recently switched to a different ISP, so I thought that might be the issue. I'm from the US, but yea I noticed wtf severe lag spikes fairly often while out grinding.
I have been questing in the same spot since last Thursday:
Thursday - Saturday = bad lags
Sunday - Tuesday = smoooooth
Wednesday = bad lags
I know my Inet provider isn't the greatest so I usually just chalk it up to that and I will generally see poor Inet performance across the board with ping tests to anywhere not very good. But, on the bad lag days above, everything else seemed fine except for L2.
Last night, I didn't do any testing but general surfing seemed fine and no one else at home was complaining - and trust me, when my sons KDR is suffering because of poor Inet, I hear it from the basement! :) But all was quiet last night.
Maybe one of the ISP between Canada and US has problem? If thats the case, well, NC can only request their ISP to talk to the other ISP to try to figure things out.
So far lag free for me and friends who are in US (east, west and central).