To reach that target they better deliver on graphics or else.....
Have games that sell multiple millions traditionally had super high-end graphics?
I don't know sales numbers but I seem to recall Battlefield 3, Crysis, and Diablo 3 were in the multiple millions. Two of those were high end. CoD games of course sell really well, and I'd say those aren't typically as high end.
I'm not convinced that the graphics necessarily correlate to sales, though later on with the PS4 and XBox1 maybe that will be more the case.