Dpreview interviewed the companies involved in the new L-mount project.
And there are many takeways
Panasonic said “This alliance is like marriage. The previous arrangement [with Olympus] was more like we were just living together. So the obligation [now] is a little more high-level.”
Sigma confirmed they will make APS-C L-mount lenses too while Panasonic said they will not do this (probably to protect their MFT market)
Leica is the real owner of the L-mount protocol. They license it to Sigma and Panasonic but would not confirm that both companies are paying for the rights.