I hope sony have learnt there lesson from the ps3 debacle. If not, ps4 sales will be dire for them. sony are already in financial difficulties.
Debacle? The news has just said they sold over 70 million ps3s. Granted that's less than the other 2 it followed, but that's still a hell of a lot of consoles
But if they got it right they may have sold double or triple that number. This is from memory so may be not 100% accurate. The original ps3 was available in 2 versions it was something like $600 in the US and £600 in the UK, also the US version could play ps2 games. They also stated that the european version was purposely shipped without the chip to allow ps2 games to be played. How stupid did sony think european buyers where ? Both my sons had ps2's now they have xboxes. There is no reason for them to buy a ps4. IMHO sony tried to take us for mugs and have been punished for it.
Like I said all from memory 
The truth is they promised it would run PS2 games, but did it in hardware (unlike XBOX360's software XBOX emulator), which bumped the price up to silly money. As it happens, their implementation, in true Fony style, was shite.
Now, remember, to win the BRD v DVDHD battle, Fony had to get gayStations out there, so shipped cheaper ones, sold at an incredible loss, without the (partial) PS2 compatibility.
Once the battle was won, to sell more, they changed the BRD spec, so standalone players were useless, and to make BRD owners buy gayStation 3s. A nasty, nasty company. I sincerely hope they go down the Gary Glitter, as thats the only justice. Sad to see a once great company act in such ways.