I don't want the OP's thread to focus on my opinion so much but you guys really aren't reading my posts and understanding what I'm saying in the slightest. I'll try and explain my point of view once more and if you disagree then fair enough, this isn't about individual games or indeed the platform they're on.
In order to declare something a system seller then you must in my opinion actually first define what that title means. It's clear some people consider a 10-20% bump in sales on here means a game is a system seller. I happen to completely disagree on this count due to the fact that whenever big exclusive games are released we get new bundles and a lot of advertising for the platform the game is on. This to me causes more of a bump in sales than the actual game in question.
Ultimately as stated earlier I believe you should look at defining a system seller as something that shifts in excess of 100% extra consoles than the previous week. Perhaps my 100% figure is too high but it should be certainly higher than what most people consider a system seller to be on here.
When you understand my personal definition of a system seller then perhaps you can see why FFXIII will be a system seller in Japan, the launch week of FFXIII will see at least a 300% boost in sales of the PS3 in Japan easily I believe. I honestly believe GT5 despite it being in all likelyhood a stellar game will not increase sales by that much in any territory. My definition of a system seller obviously varies greatly to most on here but I just wanted to make it clear I wasn't dismissing any games due out in the future on any platform simply off hand.
Personally I would love to be proved wrong and all 3 consoles get such amazing games it brings many more gamers in.