Note to self: ask webmaster to use the same CSS theme in both Labs and in the main website
We've done lots of work in performance and we added the pluggable graphics system support. Performance on the native and raster engines should be much better than it was before. Performance work also touched Graphics View (clipping, scrolling) and went even as far down as URL-parsing in QUrl
We added support for 64-bit applications on the Mac with Cocoa -- though you can use Cocoa in 32-bit too. I don't know why, after all you have more registers in 64-bit (that's what Apple tells anyways).
We upgraded QtWebKit to upstream trunk, bringing in some HTML5 features as well as Netscape Plugin support, meaning you can finally see ads on websites (who knows, you may even be one of those who click on them!). By integrating QtWebKit with Phonon, we added support for <audio> and <video> tags, without the need for a Flash video player.
We also upgraded Phonon to the latest release (4.3.0), though this technically means we're making a new release of Phonon (4.3.1). The QuickTime 7 / QTKit backend for Phonon got an overhaul and was rewritten in Objective C so that it can be built in 64-bit mode too. We also added a new, very simple backend called "waveout" for Windows CE devices that have no codecs or DirectShow.
QtScript got a debugger, both in the form of an API (see the QtScriptTools module) and a graphical debugger.
And one of my features has finally made it to the news page: improved proxy support.
Thanks to all the trolls who did amazing work for this release and to all contributors who sent us patches, ideas and feedback. We're releasing at an all-time low of Priority 1 tasks left, but feedback is definitely welcome. Please post your feedback to the firstname.lastname@example.org mailing list and we'll be sure to address it as soon as possible.