fair point. the kit zooms are 0.75oz different (190 vs 210g) in the old camera's favour, which makes it lighter overall (though you get 4x rather than 3x with the new unit (similar reach at tele end, 4mm wider at the short end). If you are being weight concious and just take a pancake prime, the difference is less than an ounce, (you get 35mm rather than 50mm equiv with the newer lens).
A good user review of the new kit zoom here
Different cameras: sure, but the biggest difference is price, and the optical viewfinder on the old E-410, which an action photographer would prefer. They both use a 4/3 sensor, albeit an updated 16mp version in the new camera, but the image quality and dynamic range isn't so different as to justify the extra $1000 for the new camera over a nice second user E-410 IMO.
The new OMD is a super piece of kit if you have the money for it. Personally, I'd take the old E-410 and spend the difference on a couple of top quality second user lenses. The difference in the image quality due to the higher resolution of the newer sensor would be more than offset by the use of a top notch lens in front of the old one.
If you have bottomless pockets, you could have the nice lenses and the new camera, but then you'd be focusing manually anyway and the whizzy new AF system is no help there. In any case, I have no complaints about the speed of the AF on the E-410.
As for the new Canon mirrorless camera (to get back on topic), I'd wait until the wrinkles of the first effort are ironed out in the next model. I hate paying big money to be an unpaid R&D tester. ;-)