Leica M9 Titanium limited edition will be limited to 500 pieces. Made out of solid titanium. It will cost an arm and a leg - probably more expensive than the Leica S2 (update: the price of the Leica M9 Titanium set will be 22,000 EUR). The frame lines will be illuminated by LED. The hand strap will come in two sizes. There will be also a newly designed holster. More details coming soon.
See more details of the Leica M9 Titanium:
Here are some twitpics from the unveiling: