Can someone please peer into their crystal ball and tell me when the new Nvidia 28nm GPU will be out? I'm expecting they will be out of my price range, which I'm fine with, but that's about the time we should see the Radeon 7950 or GTX 580 price drop

It also depends on what price point they release at and its performance vs the 7970.
If they beat the 7970 performance for the same price-point, then that would be good for prices.
Since you're asking, then you already know all this.

The 7950/7970 launch didn't really effect 6970/6950's prices much.

Honestly I've gotten tired of following all the "rumors".
Last i read was don't expect anything until April, and then i just plain quit reading all the rumor and speculation since its clear everyone is "guessing" at this point.

Now look what you did, you made me do a search...LOL
Found this...
http://www.techpowerup.com/161547/Kepler-Unbeatable-NVIDIA.html

May 14th 2012. THE CRYSTAL BALL HAS SPOKEN.

Actually, it looks like March 23rd 2012 will be the day it will be launched:

http://news.softpedia.com/news/On-March-23-NVIDIA-Will-Launch-GK104-Kepler-GTX-600-Cards-256181.shtml