Yes, the iPhone went on sale at Walmart today

[wraggster]

From the looks of our tip jar, the iPhone went on sale at Walmart today for $197 / $297, just as we expected. The plan is to attract consumers who don't shop at Best Buy, Apple, or AT&T stores, so basically Wally doesn't care about anyone reading this. We love you too, Wally. No crazy $99 4GB model or iPhone nano in sight, but maybe Phil's gonna blow us all away next week. (We doubt it.)

http://www.engadget.com/2008/12/28/iphone-on-sale-at-walmart-today/

[SkyeDarkhawk]

Before you go running out to try to buy one without a contract, you won't be able to.

The iPhone is ONLY available as a 2 year upgrade, whether you're eligible or not. 197 for the 8GB if you are eligible, 397 if you aren't. 297 for the 16 GB while you're eligible for an upgrade, and 497 if it isn't yet your time.
There is no way for them to override that either.