Considering the iPhone 4 has been around for 3 years, 4S for 2 years, and they have not previously discontinued any iPhone until it has been in at least 2 years of production, no, the iPhone 5 is not done in two days. The iPhone 5S will move into flagship position and iPhone 5 step down to a single memory configuration in the middle price range. Doesn't matter what Wal-Mart is doing. AT&T sells reconditioned iPhones for less also (online only).
The problem is too much speculation about the 5C being a low-cost US iPhone, when the first reports of it indicated it was for "emerging markets" that would imply other countries that have new markets for smart phones, but are not compatible with US LTE standards. Apple has been in talks with a major China telecom, which, iPhone 5 is currently not compatible with (see:
http://www.apple.com/iphone/LTE/). 5C=China (and other countries) with cell chips & antenna configuration that works with those carriers.
But, I'm really not sure if 4S will be the low-end model, 30-pin connectors for another year? I don't think so, but, we've got to remember, large scale production of things like this...it's a global market these days, and China has a strong momentum going for smart phones. Apple will do what they have to to get into that market.