Intel announced a new form factor at the Intel Developer Forum today. This new form factor called Balanced Technology Extended (BTX) is planned to replace ATX over time.
Intel announced the Balanced Technology Extended (BTX) form factor specification, formerly code-named "Big Water." The new form factor enables the next generation in PC system design, and is expected to supercede the ATX family of motherboard form factors over time. BTX will enable the industry to strike a better balance in thermal management, system size and shape, acoustics, and performance -- all critical attributes to innovate desktop PCs for the digital home. BTX supports traditional desktop sizes and ensures industry specifications-based small form factor PCs.
A new technology available from Intel in mid-2004, will help to simplify home networking by including a wireless access point and router functionality as an embedded feature of the PC to help minimize the need for external equipment or cables to build a small home network. Intel also previewed an instant on/off technology, allowing consumers to press the "on" button and the PC is ready in a few seconds. If the PC loses power, this technology quickly recovers without losing data or rebooting the PC under normal operation. Intel plans to include this technology on platforms in the next few years.
A PDF file with the BTX specifications can be found here, or a mirror here and here