Moodle has been chosen as the integration platform by the JISC-funded project "Serving Mathematics". This means that some fancy tools for delivering and assessing mathematics are coming to Moodle. You can find details on the project website.
The project will take up its work in September and deliver its tools before next March. The project is open-source and encourages community participation. We would love to see your comments in our forums.
One of the project's tasks is to make it easier for mathematics learning and assessment systems to interoperate with each other and with the VLE. The systems currently taking part are: AiM, CABLE, METRIC and WaLLiS. It would be nice to include others like WeBWorK.