The integration effort focused on porting Kamailio (OpenSER) module to work with sip-router core. Thre are more than 90 module, over 80 of them being converted right now. You can track the evolution at:
http://sip-router.org/wiki/devel/kamailio-integration
Once the modules are completed, the last phase is to bring to sip-router the config extensions implemented in Kamailio (OpenSER) core – about 20 functions.