@Windbane: GT4P was released in Dec. 2003 and GT4 was supposed to release just months later. The game didn't end up coming out until Dec. 28 2004, and 2005 for NA and the EU. There's heavy rumors that GT5 has been delayed to 2009 for the EU already, and I don't think it's likely that it will make it out in even Japan until the beginning of 2009.
But then again, GT4P was hardly representative of GT4 (it was essentially GT3 with slight modifications and the GT4 HUD), while GT5P seems much farther along, so we may see GT5 out this year yet.
We'll probably find out more over the next few months, and I'll change things as new info surfaces.
I mean, hey, it's better to be pessimistic now and mildly surprised later, rather than be optimistic now and extremely disappointed later.
@Akuma: A MotorStorm 2 video should be released this Wednesday.