The current 5.0 is 4951 cc. Only by virtue of rounding up is it considered a 5.0.
The old 5.0 was 4942 cc.
Nevertheless, I think a lot of the information that's been passed around over the last few days has a lot of truth to it and there is no coincidence that the surveys and "leaked" renders from Car and Driver came out at the same time. There is a lot of good information with some misleading filler to keep people guessing about whats actually going to happen. I think some of the "errors" are intentional and allow Ford give out juicy tidbits without totally spilling the beans. It's all a calculated and controlled release of information from Ford and it's got people talking, which is exactly what they want. They've been in the game for over 100 years, they aren't stupid.
The Car and Driver photo is legit. I don't expect any differences. The prices and options have not been leaked though. Those are rumors started from a recent survey that went out to Mustang owners. I participated in the survey and I saved off some of the HTML;