Microsoft confirmed this morning that the 250GB HDD upgrade will soon (Supposedly today) be coming to the US for $129. Until now, the only way to get the extra HDD space was to purchase a special edition XBOX 360 that cost around $400.
This much needed upgrade will definitely help the current lack of storage on the Xbox 360 which now needs to store downloaded TV shows and movies from the Xbox Live Marketplace.
If you are interested, I would first check www.amazon.com .