My analysis on PS4, expected components and costs:
Sony will not abandon the cell processor, they invested billions in it and all that would go to waste if they didnt use Cell, unless AMD offers 2014 technology for a late 2013 console.
PS3 has 1PPE and 8SPE, PS4 will atleast have 4PPE and 32SPEs, Cell 2 will be baked on 22nm.
Price: around $/€100
Fast Ram is so cheap nowadays, even the WiiU will feature 1.5GB ram. You can find 4GB Corsair Vengeance ram for 25 euros.
PS3s RSX is based of a Nvidia 7800GT, the Nvdia card was 300 pounds at launch:
At its launch PS3 got a high mid range GPU, the RSX in the PS3 only cost 129$, significantly lower then the price of a 7800GT
I predict that PS4 will have a HD7870 with 2GB VRAM. It costs less than what a 7800GT had cost at launch. In Europe you can find a HD7870 for 300 euros. Ofcourse this is not the price Sony will pay for the GPU, they will get a huge discount and by the time PS4 releases Sony could pay as little as 100 euros.
Sony will use an upgraded bluraydrive enabling 4 layered BDs up to 100GB per disc. Future PS4 could benefit from this size and to make the movies and sound lossless.
Price: 25 euros/dollars
Bill of Material costs:
CPU: $€ 100
Optical drive: $€25
Circuits, motherboard and other parts:
Total manufacturing price: $€350
Lets factor in 150 dollars for assembly, marketing and transport and total price is $€ 500.
PS4 will be released at $/€499, Sony could turn break-even right after launch. A huge difference with PS3, only the BOM for PS3 was 840 dollars, marketing, research and transport included the price for PS3 was probably higher then 1000$: http://www.edge-online.com/news/isuppli-60gb-ps3-costs-840-produce
I don't think Sony should release PS4 at a lower price, it will result in them losing money and people now are willing to pay more then 500 dollars for tablets and smartphones. In 2006 there were no smartphones or tablets for 600 bucks and PS3 at 599$ was odd and expensive at the time.