Sorry, but wrong. Olympus dSLR cameras are all 4:3 aspect ratio (1.33). It even states that on the link you provided!
Anyways, if you are shooting in RAW, then use the camera's native 4:3 ratio, since all other aspect ratios are just software conversions/crops anyways. If you shoot in the 4:3 aspect ratio, you will have the max data from which to do your own crops to other formats if you so desire. On the other hand, if you are shooting a whole bunch of snaps for 4x6 prints, then it may save you time to shoot in 3:2 mode.