Just to address this whole M9 thang, and the obvious comparisons which people are drawing...
The Leica has never really appealed to me enough to part with that much of my hard earned wonga for one - either the film or digital versions. Leica have always plodded along happily way behind main stream advances and truth be told they only really entered the digital arena at the nth hour when they were in severe financial doodoo.
I can understand that people buy a Leica for it's heritage, undoubted build quality and what it represents - it's an intangible thing really that you either 'get' or you don't and of course you get some pretty incredible glass - at pretty incredible prices. For me - Leicas strength is in their lenses, not in their cameras. Tell me you like fiddling about with manual focus and a split image rangefinder and I'll quite understand that attraction, but the fact is a Contax G2 will beat you to the shot all day long. I'm not a Leica hater, I admire everything it represents but for me the shortcomings aren't compensated for by the heritage or the undoubted pride of ownership.
As far as comparison between the NEX and the M9 go - they've already been made - at least as far as the Nex 5 is concerned.
Here's one where they were compared using Leica lenses on both cameras...
http://www.stevehuffphoto.com/2010/08/28/crazy-comparison-leica-m9-vs-sony-nex-5/
and another where the 18-55 kit lens was used on the Nex-5 not doing so well, but form your own opinion of whether the difference is really around 5 or £6Ks worth with a half decent lens.
http://www.stevehuffphoto.com/2010/08/28/crazy-comparison-leica-m9-vs-sony-nex-5/
Steve Huff is an M9 owner and isn't seeing a big difference between the two cameras. In the first review he makes no bones of the fact that the doesn't see the M8 as a match for the Nex 5