4 mn in December...pretty much sure abt this...so WW will be summing up to around 31 mn in total. The FFXIII release in Japan would be enormous...a reason for why a normal number like 3mn units can jump up to 4mn units. 

3.8mil

That's rather low.

Talk us through that? (Regions)

well.. right now it looks like sales might be limited by how many units Sony can ship

I'm not very good when it comes to making predictions so I am going to agree with the OP.

NA: 1.7m
Europe: 2.1m
Japan: 0.9m

i know it is, to be honist i could put here yeh 5 million 1 month world domination! but that 'could' happen and if i expect it, it wont shock me..get what i mean

if i think ok say america buys during Black friday the majority of what they will buy at xmas, then think ok Others has been selling well so they shall make the majority. then Japan will have about 500,000 FF13 and everything i get about 2.5

if i only expect small then when/if the numbers come in BIG i will be so happy and shocked..see? lol