I got an error while compiling the 3.2beta1 version of the syndication plugin, telling me that it couldn't find boost/shared_ptr.hpp. I configured with:
mkdir -p build && cd build
cmake ../ -DCMAKE_INSTALL_PREFIX=/usr \
-DQT_QMAKE_EXECUTABLE=/opt/qt/bin/qmake \
-DKDE4_KDECONFIG_EXECUTABLE=/opt/kde/bin/kde4-config \
-DAutomoc4_DIR=/opt/kde/lib/automoc4 \
-DStrigi_DIR=/opt/kde/lib/strigi/ \
-DBOOST_INCLUDEDIR=/usr/include/boost-1_37 \
-Wno-dev \
-DCMAKE_BUILD_TYPE=Release

Note that I told cmake exactly where my boost include files are. I did this to fix it:
sed -i -r 's#^CXX_FLAGS(.*)$#CXX_FLAGS\1 -I/usr/include/boost-1_37#' plugins/syndication/CMakeFiles/ktsyndicationplugin.dir/flags.make

Then reran make and it was happy.