Check out the new Olympus 4/3 system
Perhaps instead of choosing from the latest "bastardised" 35mm systems, it might be worth waiting to see where this one goes ... the potential benefits are promising - the prototype outfit probably has everything an aviation photographer could need. I guess success will depend on whether or not any of the other big names buy into the new standard mount.
It does occur to me that perhaps this is why Nikon have been quiet as of late on the DSLR front - perhaps they have abandoned what they see to be a short lived market and are planning to go for this new format in a big way. Is the fact they are already producing "digital" lenses a clue? Is Canon going to be left by the wayside with a dinosaur technology?