In case someone else is in the same situation. I just finished porting our plugin to 0.7.0 and the only changes I had to make were in SAMSON::getProxy (the arguments have changed), and the call functions of the proxies (arguments of SBValue type used to be pointers, now they are passed by reference).
We have still to test it to make sure all functionality is working, but so far it seems that was it.
Regards,
Elisa