Desroko on 09 May 2008
Leaving aside the fact that they're on different systems and only a small proportion of consumers own both, I'd say sales won't be affected. They both appeal to the sort of gamers who don't blink at the prospect of buying a couple games per month (or week).
That said, MGS4's sales will tower over NG2's. But I'm only loking forward to the latter.
