Let's get back to the topic and ignore the trolls...
I can understand the argumentation of Jono, but some of you mentioned already, this is a very personal decision, influenced by the alternatives Jono already has.
If someone does not have yet Leica M body or Leica M glasses, the decision making process will be definitely different.
If i.e. someone wants to have a small but capable camera (no DSLR) with a kind of rangefinder feeling and an OVF, there is simply no alternative to the Fuji X100 out there
I used both, X100 and Sony NEX. The image quality of the X100 is already so good for my needs, that the benefit of a potential marginal "more" IQ of a NEX 5N is no value driver for me (I will sell mine with a lot of Contax G lenses)
But the NEX 5 does not have an OVF. The optional EVF is no alternative because if you think this process until the end, you will realize that the whole NEX concept is no concept at all as long as there are no native small lenses offered and an integrated EVF or OVF (i.e. Nex7)
I do not see the point of a "Lego" build strategey, that I have to purchase this and that addionally to have one day finally what I wanted at the beginning.
The NEX body is really tiny, the offered lenses are so big, that it is more a Pentax DSLR competition or Leica M competition in terms of size.
As soon as you look at the NEX system not as a back-up for existing Leica lenses, the whole system does not make anymore that much sense. And as we all now, Sony originally did not intend to target this system to enthusiast photographers. It was meant for mass market life style people with no other system or lenses at home. Just look at the broschures and you understand my point.
So IMHO it is totally logical. that leica M users have no real benefit with a X100. They will tend naturally more to NEX system to be able to use it with their already existing glasses.
But the thread should not mislead readers. The X100 and even more the upcoming Fuji LX is the answer to a long existing wish of many photographers. And it delivers 100%.
It is not the question whether someone has the money for Leica M or not. It is a quetion whether you want to live with so many compromises at a price level this high. I used to have a M6 and know what I am talking about.
Let's face it: Leica is not the owner of a RF concept. They had never a patent on this AFAIK. They are by accident the only ones who offered it continiously over decades and went almost bankrupt with it. Others offered RF too over a shorter period of time.
If Leica would have had more money in the past, they would not have killed their DSLR segment. So this was not a choice of better system (RF vs. DSLR), it was a choice of how many loyal customers they have in this or that segment after everybody bought DSLRs from different brands.
But we are now in the digital world. Leica is no innovator here. And the question I ask myself is why I should invest a lot of money in a Leica System, that was optimized for the analogue world, with a concept of 1950.
If you just look at how many Leica M users buy now Sony NEX, and how big the demand is for the Fuji X100, I would get worried if I would be in the shoes of Leica. The next step for loyal Leica M-customers because of lack of alternatives in the past is only a small step.
With the Fuji X100 you can see how a "RF concept" of the year 2011 should look like and where the market will go over the next decades.
The X100 is for the digital world a very expensive camera. But it addresses my needs of 2011 a lot better than a Leica which basically did not change since 1950. If Fuji will offer Fullframe with the upcoming LX, we can count the number of postings here who will buy one
IMHO it is not a question of "whether", it is more a question of "when", the market share of the Leica M system will decrease significantly. If they do not respond with a better concept than minor improvements over an M9 you will see the same development as in Medium Format over the last 10 years.
Just my 2 cents...