Arduino Mega was released today. I already ordered mine from lawicel.

As stated in arduino mega page:

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.

I definitely will use those additional USARTS. The lack of a second USART was the main drawback of previous Arduinos for me.