the four-thirds user website has recently posted up an excellent article on working with the RAW files from the e-p1.
you might find this an interesting read. if you don't have time to check it out, here are the image examples. The following is an excerpt from the article.
ISO 6400 Pen E-P1 image, original camera JPEG
This image (above) was shot using ISO 6400, hand held. The camera has brightened the scene from that I recall seeing with my own eyes. To demonstrate how dark it was, the camera only got as high as 1/30th second shutter speed even with ISO 6400 sensitivity. The 14-42 lens was used again, this time at 22mm, or mid way through the zoom range, and the aperture was f/5.6. The camera's noise filter was switched off.
ISO 6400 Pen E-P1 image processed from RAW.
And this is my effort at processing the same image, but from the RAW file using Olympus Studio 2.3. The noise grain has been suiccessfully suppressed and although the image does have a softness about it if you look closely, as you can see here it works surprisingly well at Web resolution, and will be fine for small to mediun sized prints."