I noticed the OP only listed technicals which is a very bad sign and is indicative of why the PS3 was hyped to high Hell and back, but has sold only half the hardware as the Wii Let me give you a big clue:
Games, games, games, games, games
The average video game consumer gives a rats ass about specs. People buy systems for the games.
If Sony did release a handheld as you mentioned in your original post, they would price themselves out of the handheld market. I estimate at least $350-400 for the PSP-3D alone. People will not buy that when a substitute such as the Nintendo 3DS will be around the $200 price range with all the game franchises they played and loved when they were little kids back in the 1980s and 1990s.
A Sony PSP-3D as you mentioned would make the DreamCast look like a winner in sales.
