Microsoft's newly announced project SmartGlass for Xbox 360 is set for release on October 27, 2012 according to sources close to the Xbox 360 development team. Microsoft's SmartGlass will not launch with any hardware and will be completely software contained in the form of an Xbox 360 update.
The connection will be over LAN. So, your devices such as tablets and phones will need to be on the same LAN (using WiFi with the same router that your Xbox 360 is on) as the Xbox 360. It is unclear whether SmartGlass will work over IP (Internet) and connect to your devices as long as they're on the Internet. Probably not though.