First of all, the validation framework of FLOW3 made a big leap forward thanks to Christophers work. Now, in case you enter something wrong in a form, the form is automatically re-displayed, a nice error message is shown, and the form field with the error is highlighted.
Second, Jochen is working hard on rewriting the Persistence layer of Extbase - now with joins, lazy loading, and loads of other nifty things. He essentially ported big parts of the query model from TYPO3CR to Extbase, building on a relational database backend. You can see his current state in our SVN.
Third, some nice features have recently been implemented into Fluid - namely a boolean expression syntax: Now, you can write things like
<f:if condition="{object.value} == 5">...</f:if> - something that was not possible with Fluid before. And you know what? This is available for all ViewHelpers which take boolean arguments.
Again - remember that this is only my personal view on what happened in Extbase/FLOW3 development the last weeks - a lot more has happened as well!
Greets,<br/>Sebastian
PS: I'm now trying to blog more often again! Hopefully you'll like that! (Just use the comments to tell me if I should continue or stop blogging ;-) )