sorry bout that!!
I found this on thier website, apparently its good to go out of the box just like any other one, but you can apparently upgrade the HD unit
they have premade units, they are specially designed to snap into the top of the system!!!
hope it helps!!!!
what i have understood about it, is that its just a REALLY REALLY BASIC system, you dont get the 120 GB harddrive, and you dont get anything fancy! if you want a good system but arent sure of which Xbox is for you.... here is a checklist if you want to figure it out!!
i almost went with the ELITE before i got my ps3 but anyways heres all the info i think you will need
Xbox.com | Xbox 360 - Which Console for You?
Xbox.com | Xbox 360 Consoles - Xbox 360 Arcade System
The Xbox 360 Arcade console is everything you need to hit the ground running. Plug in the console and connect the wireless controller and you're playing.
Play together today with Xbox 360™ Arcade, including the Xbox 360 console, wireless controller, and memory unit for game saves.
Have fun right out of the box with five Xbox LIVE® Arcade games including:
PAC-MAN Championship Edition™
Boom Boom Rocket
Begin playing: Xbox 360 Arcade console is everything you need to begin playing right out of the box, including Family Settings that allow parents to restrict game access for younger players. Comes with a wireless controller, five arcade games, and a memory unit. This console includes an HDMI output, so you can experience your games in the highest definition possible, up to 1080p (HDMI cable sold separately).
Xbox LIVE: Xbox LIVE is where games and entertainment come alive, the only unified place where you can play with anyone, anytime, anywhere. Connect Xbox 360 to your broadband connection, attach a storage device (hard drive or memory unit) and get instant access to Xbox LIVE Silver.
Express your digital identity through your gamertag and gamer card, talk with others using voice chat, and access Xbox LIVE Marketplace.
Games: Every Xbox 360 title supports 720p and 1080i high definition resolution or 480p standard definition resolution, in 16:9 widescreen, with anti-aliasing so you enjoy smooth, movie-like graphics and multi-channel surround sound. Vibrant characters display depth of emotion to evoke more dramatic responses, immersing you in the experience.
Digital entertainment: Amplify your music, photos, video, and TV. Watch progressive-scan DVD movies and share your digital pictures with friends. Xbox 360 also instantly streams the digital media stored on your MP3 player, Media Center PC, or any Microsoft® Windows® XP 2005 Edition-based PC.
HERE IS THE HD LINK:
Xbox.com | Xbox 360 - Xbox 360â„¢ Hard Drive (20 GB)