In 3.3 the whole Viewer-Infrastructur has been reworked to make it easier to add new features in upcoming releases. Some new features where part of 3.3 (e.g. LabelProvider/Column, CellNavigation, Customizable-Editor). Additionally JFace opened up its viewers for subclassers by wrapping Widget-Specific API (ViewerRow/ViewerCell).
3.3 saw the first public release of the Eclipse-Databinding-Framework which removes the need for myiards of listeners to keep your model and UI in sync. Anbody who ever had write a Master-Detail-UI knows how hard it is to get it right.
We saw great adoption of our new API and new features added ontop of it. The most significat one is a LabelProvider which understands StyledText-Instructions named StyledCellLabelProvider. You'll see this LabelProvider in action if you open the Java-ProjectExplorer.
On the other hand we also saw great adoption of our API-Opening-Up effort which allows widget vendors to provide a JFace-Viewer-API for their structured widgets. There are 2 Nebula-Components (Nebula-Gallery and Nebula-Grid) who already adopted the concept and provide a viewer.
Thanks for the great feedback and bug reports from the community we fixed some  problems and feature request some of them dating back to 2003!
In comparison to Europa-Release we didn't introduced much new API. From my point of the main focus was to evolve the new API we provided in 3.3 and fix problems which have been introduced. If you saw how much code has been rewritten in 3.3 I think this was thr right thing (although we fairly broke no backward code anyways in 3.3).
Thanks to the community and Ed Merks and his team there's now a 2nd possibility to back up your UI with a model beside JavaBeans.
Naturally they provide integration for their EMF-Objects with 2 brand new plugins named org.eclipse.emf.databinding and org.eclipse.emf.databinding.edit. Those plugins are marked as provisional but I'm using them since day 1 in my projects and for the standard cases they just work fine and whenever a bug occurs it's fixed immediately. Give it a try and see how fast you can develop powerful SWT-UIs.
At the very moment you bring EMF into your project it opens up the door for fairly everything you and your customers ever dreamed of (take a look at the teneo to presist your model in a SQL-Database using hibernate, working with distributed objects using CDO, validating your model using OCL and much more).
On UI-Side of Databinding also many new features have been added. You have support for Inline-Editing in Table/TreeViewers (every control inheriting from it e.g. GridViewer), there's new support for Observable-TreeViewers and naturally many many bugfixes .
Naturally we are going to fix bugs and problems. I have already some bugs in my queue I can address after the Ganymede-Release is out of the doors. Looking at this back log of viewer bugs  I'm going to try to bring this bug count down a bit (say 200 is a good number).
I see a bright future for databinding and I'll restart my work on bringing all this (databinding+emf) to the web using it in my GWT-Enabled applications inside my UFace-project if time permits.
I think all people worked on the projects above have done an amazing job. We fixed many bugs added many great new features, many with the help from the community whether they filed sensetational bug reports or even provided patches. A big thank goes out to you, the community.
One more note in the end. In time of 3.4 we saw the creation of a new project called E4. It was discussed controversial in the blog space and on mailling list as you all known.
After EclipseCon I decided as a community member to take part in this effort for the next generation of an UI-Framework provided by the Eclipse Organisation and had a lot of fun until then. If you are interested in learning new things and exploring new areas in space of ui, resource-managment, model-driven development I can only advice you to take part and learn how to organize, design and implement one of the tools that will have infulence on the next generation of thousands of commercial and none-commercial products.