Some things that are still missing:

• Dead or Alive 4
• a Modchip, Teamxecuter is well place to ship the first one in weeks or months....
• a way to use it as a media center with an open source software
• samba share and not proprietary protocol which require XP/MCE

Annoying

1. noise
2. size of alimentation

but I am able to support it when I play in 720pp on a 5 meters display :-)

some sites on hacking:

• www.free60.org a wiki based site which purpose is to centralize all knowledge
• www.xbox-scene.com the reference
• www.geux.be site de reference en francais
• http://xbox.hackaday.com/ 
• http://www.xbox360-hacks.com/

Not related to hacking but some good news on games, mods http://www.xbox360fanboy.com/