Part of the old RAF site is now an NHS facility - my other half works there now. Most of the site is still abandoned though. As I understand it, the site was in "Green Belt" land but the council has been trying to get this changed so they can have the lad developed. I assume they have been successful but at present nobody has the money or will to build here. I guess it's just a matter of time though.
Shame that more photos haven't emerged of the Spitfire and Hunter that were here. From what I'm told, the annual air display attracted plenty of interesting aircraft too but of course they didn't land here.
Incidentally, regarding Coal Aston, I found a rather poor photo I took when I was a school kid at the school which was built on the hangar site. I estimate it was about 1975 showing the Blue Eagles Sioux helicopters parked on the sports pitch at an afternoon fete - they did a display in the afternoon. Now of course, I realise that they were parked on what was originally the landing field, so they earn the distinction of being the very last military aircraft to use the site - about thirty-five years after it closed?!