I rather see excellent car game made well and long than hop into Need For Speed serie makers who seems to release shit after shit every 6 months.
What PRY says is correct. Polyphony Digital began work on GT5 long before the PS3 was on store shelves. But they're a very secretive company and Kaz rarely gives interviews. When he does, he's extremely guarded with what he tells the press.
Don't get me wrong, I expect high standards from GT5 and I think Prologue was a sample of what's to come. They set the benchmark for photorealistic graphics that are nothing short of stunning. For a console game, it has a very impressive and sophisticated physics model. But there are areas where it could use some improvement. My main complaint, exactly as Juan Kerr pointed out is in regards to FFB. And I just think that spreading their resources to include nearly 1,000 cars is turning this into a much bigger project than it needs to be. That and GT Mobile.