For EPiServer 7 we still use the VPP system, while in 7.5 we use the media system. Both can serve content from Amazon S3. But I think only 7.5 comes with it out of the box.
Read more about 7.5 and Amazon here: http://world.episerver.com/Documentation/Items/Developers-Guide/EPiServer-CMS/75/Deployment/Deployment-scenarios/Deploying-to-Amazon/
To what extent, and how can CDNs be used within an EPiServer site?
Can I setup EPiServer to upload to, and serve from a CDN?
Have updates in 7.5 for the way is handles images changes this in anyway?