Hi everyone,
I was recently in contact with Wakaama [1] community (part of the Eclipse IoT foundation), and which maintains an open source implementation of LWM2M.
More to the point, they told me that the code base [3] is deprecated (it was their repo prior to joining Eclipse), and that their supported codebase is now [2].
They would be very happy if their implementation would be ported to RIOT, and would provide some support for that (they suggest whoever is interested in that contacts them through [4]).
I thought this information may be of interest for us, and in particular for GSoC project proposals on this topic.
Best,
Emmanuel
[1] http://eclipse.org/proposals/technology.liblwm2m/
[2] https://github.com/eclipse/wakaama [3] https://github.com/01org/liblwm2m [4] https://dev.eclipse.org/mailman/listinfo/wakaama-dev