I'm interested in the GTX780, but feel it's way too pricey at the moment. I'm wondering if people think it will drop in price significantly when the HD8970 is released, or when production of the GTX780 ramps up and availability improves.
Right now they are retailing in Australia for $825. I could wait till November or December if the prices drop to $600-750, but if they're only going to drop maybe $10-20 then I don't see why I should wait.
As far as I can tell, the Titan hasn't dropped at all since the release of the GTX780?
I think, as you say yourself it will depend on the price and performance of AMD's next generation but I wouldn't expect an immediately respons from Nvidia regarding the price if AMD comes out with a better "price vs. performance" card than the 780. I wouldn't hold my breath to be honest.
Neither the GTX780 nor Titan has any single GPU competition (apart from each other) and it seems Nvidia cannot produce enough of either to cope with demand: Quite a few who might have gone for GTX690 or HD7990 are opting for the simpler, quieter and more thermally friendly Titan and GTX780.
It is not known, just rumoured, when AMD will release their next gen and nothing solid seems to be known about their specs or performance.
So, right now and for the foreseeable future there's no reason for Nvidia to lower prices (unless they develop a philanthropic streak).