e-5, e-P3, XZ-1 => OM-D e-M5 ?-)
I think it will surpass the the e5 in some ways for sure. The new sensor is a good leap above the older 12mp and it uses a new processing engine but retains teh fine detail engine as well which combined with the light AA filter should go really well.
I am seriously looking at getting one but I dont think it will replace my e5 but rather compliment it. I already have the 45mm f1.8 on my e-p1 and its really really nice but on teh e-m5 it should be very comparible to the e5 and 50mm f2 if not a tad better due to improved sensor.
According to initial reports the 12-60mm focuses much faster on the E-M5 compared to the E-P3 but naturally not as fast as the e5. The 14-54mm Mark I has been rumored to focus a similar speed to the e1 whic is very usable.
I think it will be a camera that will bring Oly up the ranks cause they will finally have a sensor that can really compete with the APS-C. Not saying the Pen range was bad but it did lack when viewed against the competition.