The Due makes use of Amtel's SAM3U ARM-based process, which supports 32bit instructions and runs at 96Mhz. The Due will have 256KB of Flash, 50KB of SRAM, five SPI buses, two I2C interfaces, five serial ports, 16 12-bit analog inputs and more. This should be compared to the current best selling Arduino Uno with an 8-bit 16Mhz ATmega32, 32KB of Flash, 2KB of SRAM and a lot fewer I/O ports.
Watch the one-hour video of the Maker Faire presentation by Massimo Banzi & Alf-Egil Bogen:
