1) Faster Bluray Drive
2) 1GB total Ram
3) Improved Cell with even bigger cache's
4) Improved GPU that works well with the CPU.
5) XDR ram only in the system.

Heated/Air-Conditioned controller grips (not like the cheap fan, with a compressor)

A 4D projector that is under a secret flap

A sculpture a Kaz, like a hood ornament

A Fleshlight, with rumble features

Shiruken launcher

Fog Machine & Light Show

A proprietary CPU/GPU with some emotive name

Can end world hunger and bring world peace!

OT: I pretty much want them to stick with the PS3 or make an enhanced one but not expensive and NO DELAYS! and NO 4D CRAP!

PS4 should have.

HARDWARE:

CELL chip with 2x PPE, 16x SPE - 1 SPE reserved for redundancy, 2 SPE's reserved for the OS. --> thus leaving 2x PPE and 13x SPE's @ 5Ghz.
New graphics chip -- based off NiVida's GeForce 11 or 12 series.
1gb of RAM on CPU. 2gb of RAM for the video card.
12x or 16x blu-ray drive.
250gb HDD (if its cheap enough use a 120gb+ SSD)


FEATURE SET:
PS1 BC, PS2 BC, PS3 BC
Use XMB style interface
in-game XMB at launch.
Custom soundtracks in every game
Trophy support for all games
PSP/ PSP2 compatibility.
Cross game voice chat
HOME standard (provided its good)
Uses current PSN accounts.
Can access PSN - PS3 Store
PSN - PS4 store
Video store
Ability to take screen shots in all games.
Ability to view photo's in-game (not sideshow features though)
A good web browser...
In-game web browser access.

Finally -- good 1st party launch titles...

a Wii :)