The latest in many issues I've had with my early revision 15" MacBook Pro occurs randomly (but often) when hooked up to an external monitor. The screen will invert and then fade to black, with banding an colors fading in and out, until it goes completely dark.
This has happened with 3 different LCDs and a projector, using the DVI dongle and without it, with and without the power adapter plugged in, with the display mirrored and with an extended display, but never without an external monitor.