So just to wrap up this thread in a nutshell, DICE release via twitter I might add rather than the official website, the system requirements for Battlefield 4.
In a somewhat confusing fashion these list the recommended cards as a 7870 or 660ti both of which are as standard 2GB cards (in fact I don't think you can get a 7870 with more than 2GB, please feel free to link to a manufacturer that does one) but then goes on to show that 3GB is the recommended amount of Vram.
This of course sparks of the usual red vs green argument, a lot of which seems to be centred around some graphs of the test that was run on the early alpha version of Battlefield 4, with one of the arguments being that side A's data must be correct because its a alpha test whereas side B's data cannot be right because its an alpha test.
So to be honest all we know is that Battlefield 4 is coming and it will run on things as low as dual core CPU and 3870/8800 class of GPU as for the rest it's all marketing.
Just remember the recommended specs for Battlefield 3 were:
Recommended system requirements for Battlefield 3
•OS: Windows 7 64-bit
•Processor: Quad-core Intel or AMD CPU
•RAM: 4GB
•Graphics card: DirectX 11 Nvidia or AMD ATI card, Nvidia GeForce GTX 560 or ATI Radeon 6950.
•Graphics card memory: 1 GB
•Sound card: DirectX compatibl sound card
•Hard drive: 15 GB for disc version or 10 GB for digital version