We just completed moving most of the site to new servers. The new hardware is a lot faster so you should notice faster page loads. In addition page speed should be much more consistent now, i.e. instead of one page being fast and the next slow, all page loads should be equally fast now.
For the technically inclined: our main box is now an EC2 m3.xlarge instance with 4 CPUs and 15GB of RAM. In addition we are running a few c1.medium instances (2 CPUs, 1.7GB RAM) and some Heroku dynos. We are also using Amazon’s DynamoDB and a platform called IronWorker.