One of the benefits of having the Photokina product announcement is that current camera can be found for a cheaper price. The most sold Olympus m43 camera at Amazon is the Olympus E-PL1 (click here to see the ranking). But actually you should check out the many good deals on the tiny and “newer” Olympus E-PM1. Here is a list of links (mostly on eBay) of new(!) cameras:
P.S.: Another good deal is the GX1 with kit lens for $499 at Amazon (Click here).