only been on Icecrown since Jan (warmane too, haven't played private before) I get high ms sometimes (don't on anything else) my main gripe is all I get is DC constantly and I mean every ten mins or so the game crashes and everyone starts moonwalking. its ridiculously bad (worse when in dungeon cos I relog and end up ported to starter zone), made a ticket they said nothing to do with them but it obv is ;p
So, my issues are with my connection route, and it is intermittent.
You might want to download pingplotter, and run a ping trace to 54.36.105.148 and see where your issues are.
Personally, I have to route through several telia.net nodes on the east coast of the US, of which the Ashford, VA link is always the worst. Tonight, I am experiencing 17% packet loss through that hop.
Then, I have issues in UK and FR, with random packet loss issues as well (tonight, for example, 27% loss in the UK).
This is my main issue. Might see if it is yours as well.