dpreview Micro Four Thirds Talk forum user mskad did it, and the results can easily compare to those from a dedicated negative scanner. Here’s how he did it:

“I used my E-P1 with Nikkor 55mm f/2.8 micro to “scan” the negative, using the transparency attachment of my Epson 2450 flatbed scanner.

Then in Photoshop, inverted the image and did some curve corrections.”

See the result in his thread here.

Pretty awesome, dude!