I called a 45/55 percent split at most in North America between the XO and PS4 months ago and I'm sticking with that. It's going to be close. Europe, the PS4 should win by a comfortable margin. Japan, the PS4 will win out over the Wii U once the third-party titles start rolling out. Japan is extremely trend oriented, though, so a big hit by Nintendo or a partner could possibly make it a close race or even give Nintendo the edge.
The fight for third-party exclusives in Japan is going to be fierce. I don't really understand why but many of the big Japanese publishers like to release on only one console. Nintendo scoring a big franchise could be key. However, the PS4 should retain many of their exclusives from the PS3 generation, so they should do well regardless.
