Ref, take my tip and sit on your hands for a week or two. The D70 replacement is publicly unveiled tomorrow and this can't help D70 prices much. D50 either, come to think of it, though not by as much.
Lenses are another story. Some of those shots of mine were taken with the Magic Drainpipe - a 50-500 Sigma, which is out of this World for aviation shots and allows you to pick them off all the way aound the pattern, thus taking advantage of the best lighting/time of day. Very sharp, very powerful, but a bit big and heavy. Lots of other options, but to reinforce my earlier comment about longer lenses, my own D200 problem has led to me using a loan 70-200VR from Nikon and although a fabulous lens, it only really allows you to get what happens to be flying nearby. Much too short if you ask me and at RIAT I was 600 yds closer than anyone on the crowdside, still finding it to be an "end of nose" lens.
I will be running up the RIAT 2006 and Canberra last flight into Kemble shots over the next 48 to 72 hours, so pop in again should you wish.
Conan