Wow tough call as I really don't know much about the sales of the MGS series, but looking back at past sales of the game I can make a pretty good guess. Important things to note is that this is a huge hyped and marketed exclusive for the PS3, meaning this will almost certain give it larger launch sales, and better legs down the road. So it should sell really well considering that. Not to mention have to take into account region wise. In Japan popularity has gone down for it, but with the hype might cancel that out. But also PS3 hardware sales there are well pathetic, sol possibly not good. In America and Europe, sales for the series is usually exactly the same.
So here's my prediction for first week by territory:
NA: 400k
E/O: 400k
Japan: 150k
Total 1st Week: 950k
And I expect in its lifetime to do around 4-5 million, if PS3 sales do as well as I think they will.
