It's completely reasonable for them to postpone the launch until a few weeks after COD comes out. Black Ops will probably be one of the best selling games of all time, having GT5 released the week after means a huge amount of people will pass because they just bought a game. Now that I think of that it totally makes sense.
Obviously, people like us don't care when its released its a automatic buy on day one, but there are alot of people who buy a few games a year.
I don't understand why they have to separate best sellers launch!
1) it's not the same public
2) if someone can't buy both he will buy one, and the second one latter...2 or 1+1, it's the same $