Sorry for not knowing how to type Chinese by my computer.
I am going to add FF system too because of the sport photography not the wedding photography.
With the help of flash I don't feel much difference between these two systems (APS/FF vs 4/3) in wedding photography. Yes, FF is better in DOF to blur out background. However, it is yes or no condition sport photography at night.
I have to use E30 at ISO 3200 with f3.5 200mm (400mm as 35mm) for only ~1/200 sec for fast moving player! It is not enough! It is a no with a noisy image!
I saw the pictures from my friend on the same game with 1DMIV + 400mm 2.8 and all I can say is WOW, they are clean at ISO 3200 or even 6400!
The 5DMII may have AF problem and D700 may have a smaller mp problem. The new 1DX is a great choice but with price problem - $6,800!!!!
Another reason I stay with 4/3 is the reasonable price in USA! I can buy you some 4/3 equipments next time when I go back to Taiwan.
Olympus 300mm 2.8 expensive? $6,268 only (http://www.amazon.com/Olympus-300mm-Telephoto-Digital-Cameras/dp/B00014K3WU/ref=sr_1_1?s=electronics&ie=UTF8&qid=1319841768&sr=1-1) compare with
Canon 600mm 4.0 (even one stop smaller but same reach distance on th FF) $9,000 (http://www.amazon.com/Canon-600mm-Super-Telephoto-Cameras/dp/B00009R6X9/ref=sr_1_1?s=electronics&ie=UTF8&qid=1319812085&sr=1-1)
Nikon 600mm 4.0 (even one stop smaller but same reach distance on the FF) $10,000(http://www.amazon.com/Nikon-600mm-Telephoto-Format-Digital/dp/B000VDF5LU/ref=sr_1_1?s=electronics&ie=UTF8&qid=1319842019&sr=1-1)
at the current price at Amazon.
It is ~3,000 to 4,000 difference for only to one lens!