Information is here
5" OLED touchscreen (16:9, resolution 960x544)
additional touchpad on the back
uses proprietary flash-based memory cards
approx. dimensions: 182.0 x 18.6 x 83.5mm (width x height x depth)
six-axis motion sensing system (three-axis gyroscope, three-axis accelerometer)
three-axis electronic compass
Wi-Fi 802.11 b/g/n
Games shown/announced: Uncharted Portable, Metal Gear Solid 4, Killzone, WipeOut, Lost Planet, Resistance, Monster Hunter, Dynasty Warriors and some others
According to sources above the graphics look phenomenal and almost as good as PS3 games.
Additionally PS Suite was announced. PS Suite brings PS One games to Android-based smartphones. That sounds like a declaration of war to Apples App-Store and Game Center. There is no unified gaming platform for Android yet and Sony seems to be convinced to be able to fill that gap.
No price announced yet.