Thanks, I'll add a FAQ about location, latency, etc. after some sleep.
It's EC2 us-east at this time although we'll probably be evaluating alternatives soon. But moving off EC2 is a big step because so many people are there.
I wasn't suggesting moving away from EC2, but you might consider also going to places like rackspace, joyent or local/regional providers to offer their customers low-latency connections