Image courtesy: Quesabesde
The image on top (Source: Quesabesde) shows the reason why I still prefer the m43 system over the new Nikon CX mirrorless cameras. While the Olympus E-Pm1 you see on the right is using a larger sensor it is still less high and less thick than the Nikon 1 V1! Beside that I find the Olympus E-PM1 design far more sexy
Before you start bashing on me saying I am a fanboy, well I am NOT! I use cameras from different manufacturers and there are many things I like from the Nikon camera world (D700 and many of their lenses). But I simply cannot fell in love with the today announced Nikon cameras. The image quality of the V1 is good, but not as good as the one delivered by the m43 cameras. Check the ISO comparison at Focus Numerique. One more thing. The Nikon 1 V1 costs $899 on Amazon (Click here)! That’s $400 more than the price of the Olympus E-PM1!
And ePhotozine (Click here) posted also a J1 versus E-PM1 size comparison. In that case the cameras have about the same size but again the E-Pm1 is $150 cheaper.
Anyway, I am glad Nikon entered the market. More competition we have better it is for all of us (P.S.: Panasonic, can you please lower the price of your lenses and make them available earlier?)
Note: This is my very personal opinion. Other may have other needs and reason to like or NOT to like the new Nikon.
P.S.: E-PM1 shop links at Amazon, Olympus US store, Adorama, B&H, eBay.
UPDATE: Here is a size comparison with the GF3 made by Colorfoto.