I'm not nearly as experienced with Leica or cameras as many here, so maybe this will sound ignorant...
But my feeling is that Leica is realizing their main S and M lines have a limited markets, and cameras like the X2 are no where near serious enough for pros or even prosumer photographers...
Thus, they need new segments to go after, and currently Leica offers no legit options for prosumers and pros [including journalists, bloggers, etc] in the 3k to 5k range, which is a good size market.
Couple that with the fact that we are moving in the direction of smaller cameras with bigger sensors [look at response to what Sony is doing, and their push for FF... others will be following suit]. This makes me think anything BUT a FF on this "mini" makes it DOA.
On the other hand, if Leica can create an RX1 competitor that's simpler, with fewer features but better lens performance, better looks, and built in EVF for around 4kish, I think it opens up a bunch of new customers for Leica that were never going to wait in line to spend 1Ok to 12k on an M body + a Summicron or Summilux lens.
I'm not sure how typical I am... but I got in line for the new M and a Summilux 5O [11k + tax], then seeing what the RX1 was capable of for 28OO... it made me question the Leica and cancel my order. But then, I was just about to get the Sonya few days ago when I heard of this Leica announcement. So I'm waiting to see what Leica offers here....
If it's FF, with a built in EVF and fast fixed lens and performs well... even if the price is 1k more than the RX1, I would happily pay a premium.
But maybe I'm not that typical, so who knows!
[Also, even if I'm in love with what's released... if Leica takes a year before they ship like some of their other cameras, I still might have to get an RX1 in the meantime just to hold me over.]