It's true about the lenses. My friend has a digital SLR and we did some comparison shots between his good lenses and his not so good lenses. I was very surprised. The good lens appeared to have like twice the resolution around the edges of the image along with much less chromatic abberation (color fringing)

The imaging and processing chips are commodities. What's really important is the lens and usability. I think a good rule of thumb is to stick with the traditional film/optics companies like Olympus, Nikon and Canon.

-Dylan