I just find out that work will be done to integrate Packagekit with Software Center: http://alex.eftimie.ro/2011/05/05/gsoc-2011-packagekit-and-appstream-integration-for-software-center/ http://swarm.cs.pub.ro/~alexef/gsoc/proposal.html
I don't however see it on the agenda of UDS-O of being discussed. The blueprint that has been around for a while also has not had any activity lately: https://blueprints.launchpad.net/ubuntu/+spec/other-m-software-center-backend
Does this mean that this guy will do the work on adding Packagekit integration with Software Center but Ubuntu wont take it?