Here's just a nibble: up to 16GB of RAM.
Other rumoured specs include an AMD A10 APU (a CPU/GPU combo), between 8-16GB of RAM, 256GB of storage (which could be Solid State) and a Blu-ray drive. The usual suspects make up its connectivity portfolio and include standard Ethernet, HDMI and WiFi.
According to BGR, this hardware cocktail is capable of running 3D video games in 1080p resolution at 60 frames per second without any slowdown. That's a feat today's consoles aren't capable of.
Boy Genius is right in pointing out dev kits often have higher specs and RAM for debugging purposes, indicating the PS4 could reach the market with some comrpomises.
The new PlayStation will have a new user interface. The new UI will be better at multitasking, allowing gamers to easily switch between games and software installs taking place in the background.
When the PlayStation 3 was first launched in Australia, it was crippled by a high price tag. It was an orgy of no-compromise new technology, and although its introductory price was steep, Sony was 'bleeding money' on the console for four years. Eventually it began turning a small profit, but to do so Sony had to omit superfluous features like backwards compatibility.