If you bought an M8 from a dealer with the upgrades fitted I gather you would have to pay close to another couple of grand over the standard new price which makes a very expensive camera. Logically the M9, if and when it eventuates, will have to cost even more which would make it astronomically expensive.
I think Leica should have just left the M8 the way it was until they superceded it with an M9 ... that would be my preference at least. I think my own M8 will either be with me untill I wear it out or it dies ... or I'll sell it within the next few months and replace it with a D300.
I can see my future as being DSLR for digital and rangefinders for film. At no stage has my M8 'wowed' me enough to affect the amount of film I shoot and I don't believe that is necessarily the fault of the camera ... in spite of it's quirks and price it is very good at what it does! 🙂