It is attiny based
Has UART, SPI, I2C, EEPROM, PWM on up 6 pins (3 channels), ADC on 10 pins. Same usb capabilities of the Digispark plus Serial over USB support. 16k of flash
It will have full IDE integration including debugging
It will be compatible with Digispark shields as well as new Pro shields which will include WiFi, Bluetooth, and mesh
Launching March 24th or 25th on Kickstarter (as long as Kickstarter approves it)