Arguing against CG videos is pointless in my opinion, especially in fighing games they serve as a reward for beating the game, unlocking CG endings is what motivates me to play the game with different characters.
Several other plus points of CG videos have been mentioned here, the absence of individual CG endings marginally hurt the VF franchise, however I think Virtua Fighter 6 needs something new and I don't mean the introduction of another fighting style.
I believe Virtua Fighter 4 introduced Character Customization and those features it was a strong selling point but every game has it now, Tekken, Mortal Kombat etc have done considrable experiments in offering something new such as Cart Racing, Adventure Worlds (Konquest, Tekken Force Mode, Tekken Bowling, Tekken VolleyBall).
Virtua Fighter needs something new and fun as well.
Adding CG endings, intros etc will help marginally, may encourage younger players to pick up the game and bond with the characters but every fighting game already seems to be doing that, at the very least Sega wouldn't be missing a segment so it is still a significant factor.