Ah, what we've been waiting for, and all speculation is about.
According to posters at NeoGAF, with actual corresponding pictures (ala the CC $499 PS3 ads), Wal-Mart now has printed flyers with the X360 Premium at $349.
The post can be found at http://www.neogaf.com/forum/showthread.php?t=175076&page=7
This is a welcomed sight. With lower(ing) X360 sales numbers, and a significant - 5~7k drop on VGC numbers due to the RROD annoucement, this is sure to increase sales.
Back from the dead, I'm afraid.