Strangely enough, I actually measured the old CFL J5V (made by Spalding at that time) and the NFL game ball and they were pretty close in size. Going from memory, the CFL ball was slightly shorter but I recall the other dimensions being darn near the same. In fact, I seem to recall the NFL ball being a little larger in circumference in the middle. I think that the white lines on the CFL ball do allot to make it look larger than it actually is.
Now that both balls are made by Wilson, I'm not sure if there is any difference at all. I recall one interview with Flutie where they asked which ball he preferred throwing and he said it didn't really matter because they were both pretty much the same. Generally speaking, the guys in the NFL are also larger, so that could also make the ball look smaller in comparison to when you see smaller players handling a similar sized ball.
In any event, even if the dimensions are different, I don't think they are different enough as to cause any major issue with carrying the ball.
Ricky should tear it up but the Eskimo's will still take the Grey Cup :)