It's still copyright even if you leave the GT logo in place, you are not allowed to use any images created by the console in any way (unless you have authorisation). In GT5 case you are permitted to share images, but only via the in game feature. If you saved it to a computer then put in on this forum say it can be a breach of copyright, logo or not.
That's how I see it.
And that is how previous Law cases in court have been judged before in the UK. The court defined just 1 image frame processed through a consoles storage media, to the memory and then displayed on a screen is defined as be protected by copyright law.