(Updated with PR shots) A leak Saturday morning on Sony's own PlayStation forums has confirmed major details of the PSP Go now expected to debut at E3. Spotted in a Qore episode slipped out early, the device is as rumored and switches to a slider design that renders it much more portable. It now also has 16GB of internal memory (plus a card slot) that gives it a much greater role as a media player and signals a shift to download-only PSP games; the PSP Go drops the UMD drive entirely.

Newly spotted in the video is built-in Bluetooth support that lets users voice chat in games or Skype with any Bluetooth headset. The company also says it will be possible to tether the PSP Go to a cellphone over Bluetooth, though what features would be allowed through the link aren't known; it implies support for taking calls from the phone through the PSP itself.

Supporting the latest rumors, a Sony spokesman in the video says the Go won't replace the existing PSP for at least its initial launch and will be an alternative for those who don't depend on a library of UMD-based games. A price and a ship date aren't given.

The escaped details all but confirm an aggressive about-face for Sony in the portable world, where it has regularly struggled against its obvious competitor the Nintendo DS but has been facing added heat from the iPod touch. Although the Apple and Sony devices have different interfaces and different primary focuses, the iPod touch has been increasingly marketed as a gaming device by Apple and has long had more advanced media playback. [official shots via EuroGamer]