The price of the HD is what Black Friday is all about.... sure someone like a Best Buy or Circuit City will have one as a door buster special. (got an internal WD 160GB from BB a few years back for about $50 or $60 after the mail-in rebates - $129 up front)Downside is the price of the hard drive... MSRP is like $98 for the 20gb, and over $170 for the 120gb.
Arcade will be a perfect second 360 console for many people too i think.
Although, I am still leaning toward just building a new PC gaming rig instead of going 360. More expensive, but would probably get used more...