The president of SCE is quoted from the recent Official Playstation Magazine saying;
"It took four years and the second game took four years too. So I started calling them the 'Olympic Team.' They haven't released a PS3 title yet - of course not - they'll take four years! But they have something really, really good on the way."
Shadow of the Colossus came out in 2005, which means it has been 3 years. Does this mean a possible announcement at TGS? I'll keep my eyes open and pass on to you any info I learn or even plausible rumors that I hear.
Also, I just got ICO, considering the age of the game I'm not sure if I'll be writing a review, but I will at least write impressions. The more I talk about it the more I realize that the game is seemingly unknown to the masses of people. That must be changed.