Ok, all the planned changes for 1.5.1 are now in place and the current version already seems pretty stable, so, the current nightly build (available as an update site at http://pydev.org/nightly) will be the final version unless there's some critical bug found (so, if there's anyone interested, it'd be nice testing that version).
The major changes were:
- Improvements in the AST rewriter
- Improvements on the refactoring engine (no longer using BRM, merged with the latest PEPTIC and added/fixed lots of cases for corner-case situations)
- Improvement in the type inference engine for lists
And along that there were a good number of minor editor improvements and bug-fixes.