Focus right now is on the release of KBibTeX 0.6. A few days ago I assembled tar balls for the first beta. KBibTeX 0.6 should be quite stable as in the last few months I made only few and selected changes to the code base that would become this release. The tar ball contains a ChangeLog file that details all the nice things that have been added since the 0.5.x releases.
Depending on the feedback I get on those tar balls, I'll release the final 0.6 version some time in June (not later than July).
I also collected a small number of fixes and applied them to KBibTeX 0.5's code base, so there will a release 0.5.2 as well. It is made for conservative Linux distributions that want to minimize changes in long-term supported releases.
More active has been what is called the 'master branch' of KBibTeX. It is still KDE4-based and will eventually become the release 0.7. A vague estimate for its release will be in 6 to 18 months. This will be the last major release for KDE4, but there will very likely some minor bugfix releases to follow (0.7.1 and forth).
Inspired by other projects' recent ports and requests from users, I started a port to KDE Frameworks 5. Those of you who are eager to test it, look for branch 'feature/kf5' in KBibTeX's Git repository. The code is directly based on the current master branch (so it is not written from scratch) and looks and feels virtually identical. Still, hundreds of smaller and larger changes have been made under the hood; some have been ported back to the KDE4 code base.
This version for KDE Frameworks 5 may get released in a similar timeframe as KBibTeX 0.7, but it will be called KBibTeX 0.8 to signify the difference.
At some point, branch feature/kf5 will become the master branch for future development. Then it will be time for some more ground-breaking changes such as changes in the GUI, better configuration options management, proper Zotero support etc.
As usual contributions are always welcome. If you find bugs, please report them through bugs.kde.org. Code contributions are welcome as well, please use reviewboard.kde.org for that. Any more questions? Contact me by mail.