First of all, I said not as well. I don't know, I'm not the person to be guessing because I've never played the series, just in stores and the GT5: Concept and Prologue demo. I prefer arcade racers. That said, I want it to do well, but I'm just not sure it will do as well as the older versions.

The install base on PS3 will not be what PS1 and PS2 were, and MGS4 didn't sell as well as I'd thought it would. Usually, the first game of a series on a new system sells very well, but it didn't sell as well as MGS or MGS 2.

GTA IV's combined sales on both platforms did do as well as previous versions, but that is because the combined install base is similar to what PS2 alone was at this point.

Ratchet didn't do as well as 1-3, either.

Now, the Prologue did very well.

Name	Console	Publisher	Japan	America	Others	Total
	Gran Turismo 3 A-Spec	Sony Computer Entertainment	1.89	7.13	5.85	14.87
	Gran Turismo	Sony Computer Entertainment	2.55	3.99	4.31	10.85
	Gran Turismo 4	Sony Computer Entertainment	1.16	2.76	5.71	9.63
	Gran Turismo 2	Sony Computer Entertainment	1.71	3.96	3.70	9.37
	Gran Turismo 5 Prologue	Sony Computer Entertainment	0.60	0.63	1.63	2.86
	Gran Turismo Concept 2001 Tokyo	Unknown	0.43	0.00	1.13	1.56
	Gran Turismo 4 Prologue	Sony Computer Entertainment	0.79	0.00	0.57	1.36

But it was bundled in Europe and didn't sell as well as GT4: Pro in Japan (which was not released in US). Then again, we don't know how many people downloaded it.

Still, I think because of the precedent of the games above that it won't sell quite as well as the first iterations on the other consoles. I think even if CGI's prediction is correct of over 9 million, that is still less than GT1 and GT3, which were the first versions on the PS1 and PS2.

Any game that sells over 9 million is still among the best sellers ever, so it's not a big deal, heh.