Per our team meeting this week and after consulting upstream, the kde-sig decided kdepim-4.6 isn't ready yet and and to roll back to kdepim-4.4.x for fedora 15 (and ideally squeeze this in for the upcoming alpha release).
https://admin.fedoraproject.org/updates/F15/FEDORA-2011-1283
We'll continue to provide kdepim-4.6 in rawhide (targetting f16 now) and unofficial test builds in kde-unstable repo for further testing and feedback.
-- Rex