Rumors are circulating of a semi-pro Micro 4/3's lens coming out of Panasonic. Thus far, both Panasonic and Olympus have concentrated, smartly I think, on the consumer end with their m4/3's lenses. I'd imagine that this is because they both, probably correctly, assume that anyone interested in greater image quality will just buy an adapter and pick up some of Olympus' semi-pro and pro-level Zuiko lenses.
I've been holding out, though. This is because moving the lens very close to the sensor, compliments of the missing mirror and prism assembly, results in significant differences in the lens design. Truly, it results in some big advantages in lens design which helps to explain why m4/3's lenses are so bloody sharp for so little money. For example, the Panasonic 14-45mm lens costs roundabouts $300. The Olympus 12-60mm costs $800, yet the two lenses are similarly sharp. Obviously, there are advantages to the Olympus, but the sharpness differences aren't very big even though the Olympus costs nearly three times as much.
One large disadvantage to these tiny lenses, though, is that angle at which the light hits the sensor. Moving the lens so close to the sensor means lots of light will be hitting at sharp angles, which classic sensors can't detect. The light needs to hit them straight on.
Now we get to the interesting stuff. Olympus is now out of its contract to buy Panasonic sensors and can freely buy from Kodak, which makes CCD sensors as opposed to the CMOS sensors in most modern cameras. CCD sensors aren't as good in low light as CMOS, but they are excellent at sensing light from sharp angles. This is why Leica uses them in their M9. Leica's lenses produce almost nothing but oddly-angled light. This means that Olympus can manufacture lenses that produce angled light, in a compact body, and still be sharp as a knife. Olympus also appears to be abandoning its old 4/3's format, what with the E-5 all but confirmed as a swan song. Olympus has a loyal group of pro photogs, lots of pro lenses kicking around, and a budding Micro 4/3's market that seems more than ready to take up the mantle. All of this means that Olympus is primed to expand its m4/3's operations to comprise the totality of its interchangeable lens system.
Panasonic, likewise, has many interesting dominoes lining up. First off, the GH1 and now GH2 have garnered a significant professional following. And wherever pros go, lenses follow. The GF1 earned lots of love as a poor man's Leica, perhaps helped by the actual Leica logo on the body. Panasonic's original line-up of m4/3's lenses were good enough to actually be carried around by pros as working lenses because they were so small and light. All Panasonic would have to is release a pro-level body for the GH2 and the orders would roll in. Finally, Panasonic appears to actually be invested in m4/3's. Much more so than the old 4/3's format, which their efforts in were... half-hearted.
The first sign that m4/3's is going semi-pro, and that Panasonic will be the first one to pull the trigger is the rumored release of a 12-50mm f2.8 lens. Reports indicate that it will be large, but in m4/3's speak, large is still pretty damned small, and that it's housed in a pro body. I am excited to find out if it will be weather sealed, because that would all but guarantee a pro-bodied Panasonic GH2 (perhaps the GH3). I'd also be interested in the possiblity of both companies exploring sensor sizes. Look at the GH1 and GH2. They're easily on the top of the image-quality heap in 4/3's sensors, and much of that probably has to do with the size of the sensor. No matter their tinkering, the sensors will always be smaller, and thus a stop behind, the APS-C cameras, but I think that they can get it to the point where it's moot.