Looks like we are in for many more flavors of cameras! Fuji Xpro, rumored canon EVIL, the G1X, and who knows what more. Panasonic, Fuji, Olympus, Nikon, and now Canon with the G1X are all spewing out cameras and systems - much faster then we can digest!
However, as far as I can tell, we can break the actual technological advances into a few simple categories, cutting through all the "fluff" of all these new cameras:
A) Auto focus speed and accuracy.
B) Having a high quality VF that can be used for MF with 100% coverage.
C) Substantial advancements on increasing IQ and the DR of digital sensors .
D) The ability to package all this in a smaller, lighter, body.
Its seems like each new camera we are seeing, is attempting to score on one or more of these points.
The Nikon 1 series cameras, for example, seem to have very high speed AF, never seen before in a P&S. The canon G1X has a larger sensor then ever found in a P&S - even larger then MFT.
For me, as a canon rebel user, I see no point in starting to invest in ANOTHER "system" which means sinking money into an interchangeable system like the fuji xpro. I already own a collection of canon lenses, and the IQ on the xpro will probably not blow away my 550d. Not to mention its huge price tag ! $1,600 !!
Besides, the new bodies like the Xpro, will quickly become obsolete as technology seems to be advancing very quickly. Sinking big bucks into a body and locking into a system, seems foolish to me. Digital "rot" is devastating. Digital bodies of 2-3 years ago have almost NO value. The "active" life span of a body today is probably less then 3 years before the new models are so much more advanced, you wind up upgrading.
Frankly I see no point in the entire MFT market. The bodies are slightly smaller then the DSLR's - but at the end of the day they are not pocket size, and you need a strap and carry case. Might as well then use a DSLR with many more lens options and a larger sensor.
The canon 550d is quite reasonably sized. I'm not sure I want even smaller, making it hard to grip.
I'm going to wait for the new rebel (probably imminent). Or maybe the 60d's successor (70d?).