What changed in mobile Safari due to the iOS 4.0 upgrade?

Where can I find a list of the changes to iPhone Safari's handling of CSS, HTML, JavaScript etc.? Behaviour changes, deprecated -webkit extensions and also new features and capabilities.

I didn't have any luck with a quick Google search or scanning the Apple developer pages, and a cha开发者_如何学Cngelog would help a lot before I start attempting to debug a web app that isn't working properly since upgrading to iOS 4.x.

Thanks in advance.

---

This site looks pretty accurate from what I have observed.