The Arduino Mega is a microcontroller board based on the ATmega1280 (datasheet). It has 54 digital input/output pins (of which 14 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware serial ports), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. The Mega is compatible with most shields designed for the Arduino Duemilanove or Diecimila.
just found out about this and already cant wait to get one. Arduino is popular for its simplicity but this can be limmiting when getting into higher end projects. but finaly, it has come. with a whoping 54 (of which 14 provide PWM output) digital I/O's. and 16 analog inputs, the Arduino Mega is here. the improvements dont stop there, take a look at this...
|Input Voltage (recommended)||7-12V|
|Input Voltage (limits)||6-20V|
|Digital I/O Pins||54 (of which 14 provide PWM output)|
|Analog Input Pins||16|
|DC Current per I/O Pin||40 mA|
|DC Current for 3.3V Pin||50 mA|
|Flash Memory||128 KB of which 4 KB used by bootloader|
it has more of pretty much everything including 4 serial channels!
it does however come at a price, 40$ more than your standard arduino or picaxe dev-board. but in my opinion this board must offer the best mix of power and simplicity for the cash.