Geordi,
You're right, at the end of the day, it's the number of sales that will determine how much variety we'll all see but I do think the future holds promise. As the quality continues to improve, more and more enthusiasts are giving diecast a chance.
I agree with you on the repetition issue though, especially between differing manufacturers. I'm actually a certifiable Spitfire fan myself, but I do have a much harder time convincing my girlfriend that two seamingly identical brown/green camouflaged Spits are in fact different, when all the US planes have such wildly different nose art and such.
In 1:72, Corgi have given us a Czech and a Polish Spitfire (49003 Adolph Vybiral, AA31903 Jan Zumbach) but I would like to see something from an Amercian Eagle squadron... just so long as they don't put Ben Afleck in the cockpit.
1:72 is definitely my preferred scale but some of that larger stuff does get awfully tempting once you see it up close and play with all the moving parts etc. I've never cared much for smaller scales, but from looking at the size of the 1:144 B-52s, it is apparent that 1:72 may not be appropriate for everything!
Cheers,
Martin.