(Commentary) One thing that struck me once again while unboxing some new m4/3 lenses is that Panasonic sure seems to not mention the word "Olympus" in their m4/3 materials. Other than acknowledgement of Olympus' trademark of the Four Third and Micro Four Third names on the legalese page, there's no mention of Olympus m4/3 cameras in the Panasonic manuals. Even the reference to "compatible cameras" that takes you to Panasonic's support site drops you into an "Olympus-free" zone. Okay, I did manage to find one link buried in the updating instructions that took you to Olympus' firmware update site to deal with firmware updates for Panasonic lenses, but that was about all I could find.
Indeed, the "Compatibilities" button on the site the lens manual directs you to doesn't produce anything about lens compatibility, let alone with non-Panasonic equipment.
So, take this simple question: "I've got an Olympus Pen camera, can I use the Panasonic 45-175mm f/4-5.6 X lens on it?" The answer isn't in the manual for the lens, and I wasn't able to find the answer on the Web site the manual took me to. The box does say "Designed to be used only with Digital Camera compatible with the lens mount standard for the Micro Four Thirds System." But this is a lens with O.I.S. and a power zoom button on it. How's that play with the Olympus bodies? That's a mystery that Panasonic would rather keep secret, apparently.
Olympus does a little better. In their FAQs they won't mention Panasonic directly, but they do have a question "I have a lens from another manufacturer [sic] that has built-in image stabilization. Will I get more stabilization if I turn on the image stabilization function in this camera?" Well, that would be a Panasonic lens, wouldn't it? Unfortunately, the answer doesn't speak to the situation when the lens doesn't have an O.I.S. switch on it any more (e.g., the 45-175mm). Oops.
I get the fact that you don't want to overly promote a direct competitor, but this kind of silence isn't helping either company, as you might as well have different mounts if you can't find out what does and doesn't work and how when you interchange. Even the official Four Thirds site only answers the general question obliquely (the Olympus and Panasonic lenses are listed together, so they must be compatible, right?), and not directly (no support info that addresses the specific question I raised).
My message to Panasonic and Olympus is simple: get over the "not invented here" syndrome and use the combined force of your marketing to fight the Nikons and Sonys of the world (and eventually Canon). You have the only true system that is producing multiple products from multiple companies and giving user freedom of choice. Don't violate that by pretending the other doesn't exist.