They are on sale for $329 on Amazon and ship for free with Super Saver shipping. That's $20 less than the new lower price of $349. So if you've got the money and plan on buying one, now is the time.
<a href=http://www.amazon.com/Xbox-Console-20GB-Hard-Drive/dp/B000B43OY4/ref=sr_1_2/102-5177616-7642528?ie=UTF8&s=videogames&qid=1186714654&sr=1-2>Amazon 360 Link</a>
II've seen a few people post they were planning on buying one, so when I saw this, I wanted to spread the word. Hope this helps someone save a few bucks.
Edit: It looks like at Friday 12:51pm EST there's only 1 left in stock. The rumor was that it was to get rid of non HDMI systems, so that's probably it for this deal.