Trust me - I have the inside scoop on the new 7D MII. I also sell bridges
No one on this forum has the specs on the 7D M2, if it would ever exist.
However here are my thoughts on the matter (specs POOMA - Pull out of my A** or you call this a SWAG - Scientifically-based wide a** guess)
5DM3 - better low light performance
7DM2 - 1.6 crop so your lens are longer and you use only the center area which tends to be sharper.
Higher FPS? May be the 7DM2
Higher resolution? Flip a coin but I don't think there will be big difference
Best is to wait and see. If you need to buy something today (or very soon), then the 5D M3 is your best choice because you can have it today. What if the 7DM2 is delayed until 2014? Could happen - a year without a camera. In 2014 what you wait for next?
Get a camera and enjoy photography