Anyways, I think that given the feedback, going forward to support only Java 7 and Eclipse 3.7 onwards is what we should look at...
Still, I think that this breakage should be pretty visible, so, I'd like to keep PyDev 2.x releases based on the current dependencies and go forward to breaking the dependency in PyDev 3.
The idea would be stabilizing and doing one more release on PyDev 2, creating a branch to keep it going, doing one more bugfix-only release from that branch and then creating PyDev 3 where we can start targeting Eclipse 3.7 onwards and Java 7.
Regarding the apache commons, I took a (rather quick) look at it and I don't think they replace all that's used in the PyDev StringUtils... and in some cases (i.e.: StringUtils.join), their implementation seems to be considerably slower than the current PyDev implementation which was pretty optimized, so, I'm a little wary about making that replacement...
As for adding the apache commons, I'd like to know if you have specific things you'd like to use (if it's just one or 2 utility classes, I'm not sure it's worth the extra weight -- in that case, as their license allows, it may be worth just copying those classes).