What lesson is there to learn? You didn't prove a damn thing and your speculation is as good as mine in this case, seeing that MGS4 hasn't shipped on either platform yet.
I still find using history as an
indicative messure to be more telling than baseless speculation. The facts are:
- MGS2 while a relatively good port sold disappointing on Xbox. And how many of those already played it on PS2? Not many. And that's on a platform that had Halo sell millions and even move a lot of consoles.
- Xbox360 is selling very similar to Xbox... an indication that many Xbox consumers have upgraded to Xbox360, after Xbox software and hardware has been droped completely? Very likely.
So why again, should MGS4 sell millions on Xbox360 again? Because all MGS fans have already gotten a Xbox360? Doubtful...
This discussion is as gold as when Capcom went exclusive Nintendo and realized that the games weren't selling as well as the previous games on the PSone.
If Microsoft would get Konami to bring MGS4 exclusive to Xbox360 - then that would be another topic and would probably ensure quite a lot of sales. One from me included.