A company spokesperson said the extra time is to "continue to balance and enhance the game's multiplayer, one of the key features and focuses during the development of this ambitious sequel."
Most of the time similar genres avoid butting heads, even if they appear on different consoles. We'll have to see how huge-but-casual Wii crowd competes with the devoted SOCOM fans.
I am willing to bet that they looked at what GoldenEye did right and want to incorporate as much of that as they can. :-)