I'm interested in trying out Olympus' new OM-D E-M5, and since I'm used to using a normal prime (and just spent some time using one on Fujifilm's new mirrorless EVF camera), I'd like to try that combination.
Olympus doesn't currently offer a normal prime, though — there's a wide-angle 17mm (equivalent to the traditional 35mm focal length) and a portrait-range 45mm, both of which look nice, but there's no 25mm.
But, Panasonic offers the drool-worthy Panasonic Leica DG Summilux 25mm f/1.4 ASPH. I know Micro Four Thirds is a shared, semi-open standard — but there's compatible and then there's compatible. Even the best specifications have areas of ambiguity, and camera makers have the most incentive to test compatibility between their own products. With a modern electronic lens mount, where the lens itself has a microprocessor and its own firmware, it seems like there's a lot of potential for things to go subtly awry.
If I get this combo, will I be giving the camera a fair test, or will I find myself struggling with quirks that I wouldn't have if I stuck with Olympus lenses? Will there be any problems with focusing speed, image stabilization, or the like? (And of course, there's the flip question: if I want to use that lens, is a Panasonic camera the best place to attach it?)