@ mousemonkey,
You have your history mixed up then
8800GT was a mid-range product and it launched on October 29, 2007
GTX280 was a high-end product and it launched on June 16, 2008
http://www.gpureview.com/show_cards.php?card1=544&card2=567
If we look at the performance, GTX260 216 ~ GTX660Ti, GTX275 ~ GTX670, GTX285 ~ GTX680.
The difference between GTX260 216 and GTX285 was about 20-25% I recall. However, HD4890 dropped at $269 which delivered far better value than GTX285 at that time.
Today, HD7870 is already going for $200-225:
http://slickdeals.net/f/5156072-HIS-IceQ-H787Q2G2M-Radeon-HD-7870-Sleeping-Dogs-200-AR-Newegg
http://slickdeals.net/f/5145404-Asus-Radeon-HD-7870-DC2-2GD5-GPU-2GB-DDR5-DirectCU-II-dual-fan-cooler-223-49-AC-AR-20-free-Sleeping-Dogs-game-SuperBiiz
That makes a $290-300 GTX660Ti an extremely tough sell for non-overclockers looking for great value.
Overclockers would be way better served for something like a Gigabyte Windforce 3x 7950 OC for $310:
http://www.amazon.com/Gigabyte-Mini-Displayport-PCI-Express-Graphic-GV-R795WF3-3GD/dp/B007581QHG/ref=sr_1_1?ie=UTF8&qid=1346986760&sr=8-1&keywords=hd+7950
NV's price/performance right now is out of sync. While GTX670/680 offered great price/performance when they launched by undercutting 7950/7970 cards, NV hasn't dropped prices at all while after-market 7950s have fallen from $450-500 to $300-320.
NV doesn't really have an "8800GT" or "GTX460" bang for the buck this generation. GTX670 is $350-400! Worst of all GTX650/660 cards are launching September 13th but now HD7850/7870 cards dropped so much that it's almost meaningless for the market. I am hoping NV launches with a full line-up much closer to HD8000 series when they launch GTX700 next year. I mean HD7750/7770/7850/7870 launched in February-March and it took NV more than 6 months to complete the line-up. This situation has hurt us gamers greatly!!