It's official that the premium Xbox 360 is now getting a $50 price drop effective immediately.  This drops the 20GB model from $349 to $299 which was the launch price for the original Xbox. It will be interesting to see if the other two models will be getting a price cut now or if they will be announced at E3.  I'm thinking this may very well be Microsoft clearancing the premium Xbox 360 to make room for a new premium model that will have a 60GB HD and maybe have some other features. 

Update: There are two fairly related items here.  One is the Xbox 360 Elite is selling for $399 (-$50) currently on Amazon.  This seems to be just at Amazon.com so I'm not sure if this is a true price cut and Amazon is just dropping the price now instead of waiting for announcement or if Amazon is having a sale.

The other news is that Microsoft has confirmed that a 60GB 360 is on the way that will retail for $349 and will replace the 20GB unit.  I would assume that the price would eventually drop to $299 once all the 20GB units have been sold.  I'm surprised they aren't bundling those 20GB HDD that sit in stores with the Arcade model. 

Source:
joystiq.com - xbox-360-elite-for-400-at-amazon
joystiq.com - microsoft-confirms-xbox-360-60gb-for-349-20gb-now-at-299