Though I am a Sony fan looking at how the respective companies are positioned I believe that Microsoft will perform better overall as they have the USA locked down while they should improve somewhat in Europe and Japan will be a non factor for them as usual.
Nintendo I predict will sell less hardware overall as I don't foresee the Wii U having the same sales success as its predecessor.
Sony is a lot more unpredictable but I can see them doing slightly better compared to this gen overall.
So having said all that these are my predictions for the main 3 regions
USA- 1. 720 2. PS4 3. Wii U
PAL - 1. PS4 2. 720 3. Wii U
Japan/Asia - 1. PS4 2. Wii U 3. 720
I am confident for all regions with the possible exception of Japan where it could be too close to call between Nintendo and Sony consoles.