A 270 mm focal is not enough for a wildlife safari (400 mm would be the minimum, probably), but it's good enough for taking a few interesting shots at a zoo or a nature preserve, for instance. I think the photos in this post are a good example of that. They won't get me on National Geographic, but I'm quite proud of these first results.
I can't avoid thinking it is weird to have a camera that uses only a portion of the image produced by the lens. It seems like a terrible waste of high quality glass... But as long as the sensor's resolution is good, the 2x "magnification factor" one gets from the 4/3 system may actually be welcome.
Olympus E-P2 + Zeiss Sonnar 135/2.8