I dont trust those "leaks". But I still wait for the Final releases of the 600 series. Im not a gamer and perhaps never will be, but theres some points to also consider when talking about the AMD/Nvidia war:
Workstations? CAD? CFD? Computing at all? Quadro/Tesla vs FireGL etc? Theres so much more to a battle than just the names of parties and ONE of multiple markets for the products!
For example Nvidia (in my opinion) is the number one when it comes to GPU computing/GPU programming, because they were the first ones to make the GPUs ressources available to programmers officially and by "comfortable" C programming. Only Nvidia runs CUDA; consider that
Plus all other new GPU computing solutions like OpenCL and OpenGL of course, all will work on Nvidia, whereas ATI "only" provides OpenCL/Sream and OpenGL. In some applications an ATI computes a nice deal faster in OpenCL but then again it is also a matter of programming, and GPU computing in both VFX and consumer applications is still not at its peak state of development.
So when I (and I do simulations/vfx/rendering) look at those tables and see the number of cores and bus width and clock speeds, then I would buy such a card no matter what, because CUDA is something not to be underestimated. Actually if I was damn rich I would buy a Quadro right away because they have 6GB of ECC memory (6 ! ! !). My GTX470 outperforms my dual-X5650@ 4.1GHz by x3 and more in some computing situations. Think that! Price/performance ratio can NOT be better in such cases. AMD? well...no CUDA. More apps with OpenCL and I will consider ATI.
DIE size: They HAVE to make smaller dies because on every single wafer you have a certain probability of faulty chips. The bigger die DIE, the higher the risk of loosing more chips. So it makes no sense to increase DIE size (plus heat issues as already mentioned). Bigger DIEs may even mean higher cost per chip as you loose more.
Nvidia catching up to AMD rather than owning ATI: nobody asked me but really, it depends on the applications. Period.
More thoughts but...yea, nobody asked XD But Im still waiting for the GTX6xx and when theyre there and do not deliver, I will be happy to buy 580 with 3GB much cheaper then.