I can agree with some of these busiines-related reasons, as practice in PGR2 showed that both Ferrari and Porsche dumped thae logic of "our cars must be the best in the game if you want them in". Untill the PGR2 Ferraris and Porsches were always the best cars in the game.
I remeber some interview with Kaz form late 90's when he talked about not having Ferrari in GT2. He was talking about some normal street cars like Supra or Skyline are having better performance then Ferrari when tuned-up. I guess that Ferrari didn't find wery well that some 65000$ normal japanese car could ouperform theirs 150000$ supercar.
But times had changed. Maybe the time for F&P in GT series has finally come. I'd love to have them there, to do some 2P races with my crew like SLR vs. Enzo on Nurb or SL55 AMG vs. Modena on Grundenwald. Not to mention 300SL vs 250 Dino on Trial Mountain, I guess I'd cry during that replay....
And if they're not, do we get something out of it? How bout a punch in ye face?
Seriously though, I was told that KY said the Nordschliffe wasn't in GT4 (ok it may still not be, but very likely it is). But it turns out its in Prologue. Like others have said, if they're in then kool, adn if they're not, I've lived this long without them in the GT series so..... Also I wouldn't actually reall want to drive them, just thrash tehm with my Noble M400 or Tuscan T400 .
Although the only Ferrari's and Porsches I really want to drive are:
Ferrari 512M 70's sports car,
Porsche 917 ,
Porsche 956
Porsche GT1, GT2, GT3 race cars
and a Ferrari F40 LM
I must say though, I find it funny that 6 pages of speculation about whether there are going to be Italian Exotics in GT4, purely based on hearsay that someone somewhere heard someone say that somewhere someone saw a video where someone was testing a Ferrari and someone near them said "Gran Turismo 4", is ok.