Quote Originally Posted by Digital Foundry
It was a pleasant surprise not just for us, but also for many game developers out there working on PS4 titles now and completely unaware of the upgrade - a final flourish to the design seemingly added in at the last moment to make PlayStation 4 the most technologically advanced games console of the next gaming era.
Source: Eurogamer/DF

Naughty Dog lead Engine and Graphics Programmer:

John Carmack
I can’t speak freely about PS4, but now that some specs have been made public, I can say that Sony made wise engineering choices.
Randy Pitchford
Thanks for the great event in NY @playstation - Very pleased with the commitment to 8gb of GDDR5 memory. Other specs are beautiful too!
Tiago Sousa [R&D Principal Graphics Programmer at Crytek. Worked on Far Cry, Crysis 1, 2 and 3 + all CryENGINE iterations]
8 GB unified mem as baseline for next tech iterations makes me very, very happy. Fun times coming ^_^
Stefan Boberg (Frostbite Technical Director)
"Dev-friendly platforms FTW"
Johan Andersson
Rendering Architect at DICE working on Frostbite and future DICE/EA games
lots of memory is essential for both the CPU & GPU to create large & alive game worlds

If Killzone was running with 4gb gddr5. Well fuck. Great move by Sony providing they can shift the hardware come release. Developers seem very, very happy with this.
Epic co founder seemed very happy on Game Trailer's after show

*slow clap*