September 18 (my birthday!) to the 23 this 2012, Photokina will be happening in Köln/Cologne Germany. It's probably the better world show for photographic equipment. For some reason, I feel the Germans take the shows more seriously and less like a media circus. That may be a mistaken assumption of mine.
Usually, Olympus announces their new products the Sunday before the show starts. I'm expecting 2 new models to replace the current 3 Pen models. There should also be a new OM-D series body, but knowing how Olympus can be slow about such things, it will probably be an announcement and the body will arrive around March of 2013.
I also expect that Panasonic will introduce their DMC-GH3 there with a few goodies and most likely, a new professional Four-Thirds video camera/camcorder.
During the show, Zeiss will likely introduce another new lens for micro Four-Thirds for later availability in 2013.
Strangely, I expect there to be a contingent of iPhone-ography accessories. It's about this time that Apple will be introducing their new models, so it could be difficult timing if cases have to be revised to hold the accessory lenses.
I'm mostly interested in Olympus' new OM-D series model and Panasonic's GH3, as they're both to be aimed at a more professional market than previous mirror-less system cameras have been. I suspect that they'll be a bit bigger to accomodate larger, heavier lenses, and bigger hands. That doesn't mean they'll be as big as the Nikon D7000 but likely somewhere in between that and where the current models are now.
Olympus would do well to create a model that's like a slightly smaller E-1, rather than a somewhat bigger OM-4Ti. As I learnt in the past, the OM-1N was rather slippery and heavy lenses were a problem but their IS-1 was quite manageable, and also the E-10/E-20 models.
As far as Panasonic goes, the GH3 can't help but be better. They'd hired the firmware hacker that had been enhancing the GH2's firmware, so maximum performance should be expected. Hopefully, they'll make it so that the GH1 and GH2 users would have no regrets in upgrading and the Canon 5D MkIII users will have more than a little video envy.
There should also be a surprise, but who knows if anyone will see anything out in public.
Update this week: the person in charge at Olympus has stated that they're working on a (not micro) Four-Thirds body to replace the E-5, to get the most out of those lovely HG and SHG optics that are too cumbersome to be used on the E-M5 and Pen series. That's welcome news. Hopefully, the body will be announced before or at Photokina and be available in spring 2013 at the latest.