The Acer Predator G3620 which will be released on June 25 has a GTX 660... so most probably (really, really, hoping) that the GTX 660 will be announced and released before or shortly after June 25.
Well, it might just be the OEM's but it would be nice to see the actual card and have some performance tests on it albeit being an OEM. Of course, in just a little while longer after the release, other companies will be releasing their GTX 660's... hoping the Gainwards would have a Phantom version immediately LOL
Anyways, it would have the same chip as 670 and 680, GK104, but of course much more affordable for casual gamers like me.
I was juggling between getting a GTX 560ti with 448 CUDA cores or break the bank with a GTX 670. I have to wait like a month or so to replenish my money spent on my current components, and if this is true, then I can surely get a midrange Kepler card as early as next month (breaks my heart to see the empty PCI-e slot in my case LOL)
Here is the link to the article I read: http://wccftech.com/nvidia-geforce-gtx-660-images-leaked-launching-25th-june/