The Leica 50mm f/2 APO-Summicron-M ASPH appears to be delayed here in the USA. All of my sources indicate nada as yet.
Maybe it’s just delayed ~2 weeks due to the hurricane over on the east coast, or just slightly delayed— not uncommon for hand-assembled Leica lenses, no big deal, hopfeully soon.
Update Nov 13, 2012: a source I deem reliable tells me that the 50/2 AA has been delayed to March 2013.
When it arrives I’ll be comparing the 50/2 AA against the 50/0.95 Noctilux ASPH and the 50/1.4 Summilux ASPH, since the new 50/2 APO might well be the best 50mm yet made, though I do wonder if that new Zeiss 55/1.4 might give it some serious competition (though not on Leica M).