Ha. Really? If I recall, the only thing shown at E3 05, which was the first showing on how, POSSIBLY, a HD GT would look like, was the Vision Gran Turismo trailer, which used the same engine as GT4 with more cars only.
Even GT HD which released with the PS3 on Europe in 07, was also using the same engine as GT4 plus some few touch ups.
GT5 as we know it in form and shape has only been trully know since late 07, early 08, which gives us almost 2 years more or less of true wait for GT5.

Just an honest question here, are you even planning on getting GT5? If not, then why do you care?

Just because they may not have been able to start coding yet, does not mean that development had not started. All of the art assets, and detailed car models could have been worked on during that time.

take it your not a game developer....... you need code before you can do well anything.

Indeed it could, but most people seem not to even take in consideration that PD wasn't working solely on GT, and in this 5 year span they have released other games as well. Plus, once again, the public has only been truly waiting for GT5 since it's unveiling at late 07/early 08.
You can say that people were expecting it, but the same can be said for people expecting for other games that won't come out or aren't even planned to come out (FFVII remake syndrome).

there are 4 games in the must have section in my 2010 list heavy rain, Mag, God of War 3, and above all of them is Grand turismo 5....... i also want mod nation racers so thats 5 games

I never played a GT before because I'm not into these kinda games, but I'll probably try this one out just for the hell of it lol.

@evolution_2wo

Then before you even post something like you did in the OP, do some actual research. I'm not downplaying Forza, I have it preordered and getting my copy at the 23rd, but there were so many flawed points in your logic that it just seems that you're bashing GT and PD just for the sake of it.

First announced May 2006 at E3

Probable WW release May 2010

Well its going to be a 4 year wait.

But your right not a 5 year wait.

Utter Rubbish