IMO, the first trailer will create hype for the casual players (99% of the buyers/players) but for the hardcore fans (1% of the buyers/players <=> us on gtplanet) it will be another story...
Their trailers are always the same, the same kind of shots, the same kind of camera rotations, the same faked sounds, the same "no atmosphere on track", the same "no human drama", the same "not a single sign of real career mode"... I'm not a kid anymore, if GT7 first trailer is the same as always but simply more beautiful, I will not be hyped.
Don't get me wrong, GT6 is a good game but the series stagnates for so long... For me the last huge improvements was GT4 with the new photo mode and a huge amount of content. Since then we only had the legal minimum evolution (online, better graphics, better physics). We've seen nothing about a real craeer mode with real AI, real damage and real atmosphere ! Kaz said himself that GT6 was supposed to be about human drama ... Worse still, B-spec is a downgrade, rallye is a downgrade, content is a downgrade...
To be honest, I connect everyday on gtplanet forums with the secret hope of finding the news about GT7 that will proves me that I'm wrong.
PS : Everybody talks about the course maker and the fact that they should release him before they announce GT7. "Breaking news !" -> Nobody cares except us, a few dudes here on gtplanet. Even if they choose to not release the course maker on GT6, it will have absolutely no impact on GT7 sales.