The device will run Android 3.0 "Ginderbread" and will feature a large display, something between 3.7" and 4.1" with WVGA or better resolution. The processor will likely a 1GHz Snapdragon and it may have a 5MP digicam, although the specifications aren't finalized yet. The phone is mostly black with some silver highlights, while the gamepad area is white/silver in color. Here are some details about the software side:
On the software side, it looks like the device will be running Gingerbread (Android 3.0) with a phone-specific skin, and there will be a new area of the Android Market specifically for the games. That content will be initially accessible only by the halo device, but from the sounds of things, these titles might be made available to other Android phones if their specs and button layouts meet requirements. Games will be graphically in the range of PSX or PSP games, meaning true 3D gaming is headed to Android. Titles currently being shown off seem to be focused around some older PSX as well as new PSP offerings, with God of War, Call of Duty: Modern Warfare, and LittleBigPlanet possibly on tap, and future plans for titles which incorporate augmented reality features.
In terms of release, it's possible that the phone and ecosystem could be introduced as early as October of this year, but we have yet to confirm.