It's Capcom we talking about. For Vergil not to use Yamaot implies they gonna code brand new weapon for him, and I highly doubt they would be motivated enough to do it.Of course. I'm not even coming close to suggesting that Vergil isn't playable. I'm just saying that thinking he wouldn't have use of Yamato as seen in the trailer is just as ridiculous as thinking he isn't playable. My point is that just because we aren't absolutely sure doesn't mean that we can't make extremely obvious assumptions.
On a less likely note, I agree that having another Vergil boss fight tailored for this game would be mega, ultra sick.