Currently the latest version of kdepim is available in experimental. According to our limited tests it's working way better than kdepim 4.14 (more stable, more performant, less bugs). However migrating from one to the other is not a trivial process (distribution wise, hopefully not for our users).
Among the drawbacks in the new kdepim: knode, ktimetracker and kjots were dropped from the official kdepim components. kjots is now an independent project, not tied to the kdepim release cycle. But more importantly, knode and ktimetracker are not maintained upstream any more, we are temporarily still shipping the old KDE 4 versions, but we will drop them after stretch unless they get new upstream maintainers.
To iron out the wrinkles that are surely still there, we are now planning to start a transition for kdepim, effectively blocking all kdepim related packages in unstable until the transition is complete. This will allow us to keep the current kdepim in testing unchanged until kdepim 16.04 is ready to migrate fully to testing.
If you want to test the new kdepim versions right now, please use the version in experimental, as uploading all the packages to unstable will take some time until there is a working kdepim in unstable (mixing experimental and the unstable uploads should be fine).
If you depend on having a working kdepim, please avoid installing the new kdepim packages that will be landing in unstable in the following days, until all the components are available. We expect this will take a couple of weeks, we will post another entry when the packages are ready in unstable.
A list of the binary packages involved in the transition can be found [here].
If you find issues in the new packages, please let us know either via irc in #debian-kde, the kde mailing list firstname.lastname@example.org, or send us a bug report (please make sure that it wasn't reported before).
We'll send an updated note when kdepim is fully uploaded to unstable.
The Debian Qt/KDE Team.