Sort of. Because AMD is in a cash-crunch right now. They got a profit (finally!) after so many quarters of hemorrhaging money like there's no tomorrow, but if you look at how much they actually earned in raw profit, it was roughly the amount earned by the sale of their Singapore facility.
399$ is good, if it does come out. But AMD needs money. Although we may see a future price drop, I'd wait until I call the price at 399$ yet. I'd say after the GTX 780 Ti comes out, we might see the R9 290X and R9 290 Non-X drop in price. But not at launch.
Also, I hear rumors from Linus, Elric, Videocardz.com and other places that we'll see partners coming out with custom coolers in late November, December, or even January of next year. The issue is production.
Also, remember that the GTX 770 can't compete in terms of performance versus the R9 290 Non-X. It's me more comparable to the GTX 780, really, especially once partners come out with custom cooler designs.
Personally, once the R9 290X and 290 Non-X come out with non-reference coolers and non-reference PCBs, I think we'll see nVidia's new price chart go something like this:
GTX TITAN - 899$
GTX 780 Ti - 649$
GTX 780 Non-Ti - 549$
GTX 770 - 349$ (4GB for 399$)
GTX 760 - 219$ (4GB for 259$)
I'd also be interesting in seeing if nVidia plans to launch a GTX 760 Ti, GTX 750 Ti Boost and GTX 750 Ti Non-Boost. Those could be some game-changers for entry-level gamers.
If nVidia is planning to launch such cards, here's what I'd expect:
GTX 760 Ti = GTX 670 Overclocked and Rebranded (roughly on par with GTX 680 performance, maybe a tiny bit less, possibly using GTX 670 shorter PCB but I doubt it)
GTX 750 Ti Boost = GTX 660 Ti Overclocked and Rebranded
GTX 750 Ti Non-Boost = GTX 660 Overclocked and Rebranded