Using the most scientific tool known to man, youtube we can clearly see GTAV is still very revelant.
http://www.youtube.com/watch?v=QkkoHAzjnUs GTAV trailer already has 9.5million views on youtube
http://www.youtube.com/watch?v=TC2yMKMENdg Halo 4 trailer already has 6.4million views
Obviously Halo has an advantage in USA preorder charts because halo is only coming out on one system and is a bigger IP this generation in America.