Upload & Sell: On
Eh...there need to be significant improvements in continuous autofocus before I'd want to use the E-M5 for weddings. In single shot, it's fantastic, though for flash use, I'd rather use a GH3, as Panasonic's AF is faster in low light and far more precise (much smaller AF areas possible).
Image quality wise, I think you could easily create great images with it. There are fantastic fast zooms now, and really high quality primes with a sensor that has excellent dynamic range and fairly good high ISO capabilities. Pros shot tons of weddings with 1D Mark IIs, and the OM-D is better than or equal to that camera in essentially every image quality metric, and even in single shot autofocus performance (though the mark II crushes in in continuous AF).