After a bit of digging, it looks like the game server will be hosted on Amazon’s North Virginia (USA East Coast) data centre.
This choice makes a lot of sense, as it should mean decent pings for North Americans as well as Europeans, which are likely the major markets for this release. Unfortunately, other regions may get sub-optimal performance, but I’m sure they’ll add new servers in different locations at a later point in time (with Amazon AWS, this is extremely simple and relatively cheap to do.)
I’m curious what ping/latency we can all expect to see. You can test yours here: http://cloudharmony.com/speedtest-for-aws:ec2-us-east-1
EDIT: Use this link for quicker testing (no DL speed test): http://cloudharmony.com/speedtest-latency-for-aws:ec2-us-east-1
My result:
Of course, this is not a perfect test, but it should give us a general idea. 
