The major changes in this version will be the introduction of a pep8 analysis (it must be enabled in window > preferences > PyDev > Editor > Code Analysis > pep8) and scope selection/deselection (Shift+Alt+Up/Down).
The internal Jython version that PyDev uses was bumped from 2.1 to 2.2.1 to support pep8.py -- Jython 2.5 was discarded as an option because it became too big for PyDev (the PyDev distribution with Jython 2.2.1 has 7MB, if it went to Jython 2.5, it'd be around 14MB, so, I think it's not worth making the download twice as big just for this upgrade).
Also, as a plus, as Jython 2.2.1 is still based on the same grammar structure (JavaCC) that PyDev uses, so, I was able to give it a boost and provide some performance improvements that had been done to the PyDev grammar (Jython 2.5 uses Antlr, which seems to be one of the main reasons it became so big).
As a nice side-effect of this change, the PyDev startup seems to have improved somewhat (Jython 2.2.1 seems to start up faster than Jython 2.1), and now the Jython sources are included in the PyDev project (and not only a jython.jar), so, I can fine tune Jython itself for some PyDev use-cases (as it seems PyDev won't go for Jython 2.5 anyways).
There are also some critical bug-fixes in this release (an out of memory error when dealing with PyOpenGL, one cache issue which could make the pythonpath become wrong in memory and one deadlock were fixed).
So, anyone interested should get the current nightly build to see if all is working properly as an official release should be issued later this week (the current version should be the one released unless some critical issue is found in the meanwhile).