I've seen this statement on the Phoblographer review of the EM5 and it had me thinking.
Here is the link:
Review: Olympus OMD EM5
First of all, design wise, the extra latitude in the highlights (some people say they cannot even blow the highlights, even if they try), supports such a claim.
Then, there is this "crazy comparison" on Steve Huff's page:
Crazy Comparison! The Olympus OM-D E-M5 vs Nikon D800 vs Leica X2 for High ISO | STEVE HUFF PHOTOS
From what I can see on 100% crops there, the EM5 seems to even have a noise signature similar to film grain characteristics.
What do you owners of the EM5 think? For me at least, such "image character" is very desirable.