The Nikon system contains two options. While the J1 has an inbuilt flash, the V1 doesn't - but it does have a port for plugging in an optional accessory flash which can be bought separately.
It's worth noting that the Canon EOS M has a hotshoe which allows for any currently compatible Speedlite to be attached to the camera.
Canon EOS M vs Nikon 1 viewfinder
For some people, a viewfinder is a dealbreaker. If you're one of those people, you will be disappointed by the Canon EOS M, which doesn't have one. Canon also says that there are currently no plans to produce one.
It does have a hotshoe though, to house an optical unit, should Canon change its mind based on customer feedback.
The Nikon 1 V1 by contrast features a 1440k dot TFT EVF. The J1 has no device - and no way to connect one either.
Canon EOS M vs Nikon 1 ergonomics
One of the reasons Nikon included a smaller sensor in its camera was to keep the body size down, however the Canon is actually a tiny bit smaller than both the V1 and the J1.
Weight is very close, coming in at 277g for the J1, 294g for the V1 and 298g for the EOS M.
Canon EOS M vs Nikon 1 price and release date
Ah, the biggest bone of contention - pricing. For now, the Canon is significantly more expensive than either of the Nikon cameras, but this is most likely to be because it's a new release.
Current RRP for the Canon EOS M with the 18-55mm kit lens is £769 (around $1,203). By contrast, a Nikon 1 V1 can be picked up for around £479/$749, and a J1 can be had for around £340/$499.
It's worth remembering however that on release date, the RRPs for the V1 and J1 were £880 ($899) and £550 ($649) respectively.
Obviously, the V1 and J1 are already available to buy, while the Canon EOS M release date is expected around September.