DISCLAIMER: the following is a conspiracy theory and joke only:
What if Intel did this to try and stop SB from cutting into their grand plan? I mean, with how great the performance was I can't fathom Intel being able to surpass themselves for a while. Maybe they realized they'd released too good of a product that wouldn't allow them to change sockets and nickel and dime people every generation. Maybe they were afraid that people would buy this and realize there's no need for more power. What would Intel have left to do?
The AVX or what ever it's called transcoding performance was insane. You could beat an i7 with a GTX580 with just a SB CPU using that whole AVX(mediashowesspro called it something else). It's the one area that made me somewhat sad I didn't go with Sandy Bridge.