I know some of my friends at school just bought the system for that specific game over the ps3.
Same. One of my friends recently admitted that he hadn't really put any thought into getting a 360 and had bought one purely for Halo 3.
His lack of research really showed too. He had plugged it into his Bravia HDTV with analog cables because he didn't know what 720p was. Suffice to say, Gears looked awful. But I think he's using component now.
Also, when I asked him if he was worried about the red rings he said that he had never heard of them and then told me that he had been informed by the guy at the shop that the PS3 was the one with hardware issues!
Clearly, people like that should try and put Halo 3 out of their minds for just a second and evaluate what they're actually buying rather than what games they will buy for it.