Right, but I'm saying you were comparing to the power nine in the wrong way, as Power Nine are engine cards not win cards. They make combos happen! :D
Anyways? How big a deal is timevault? Sort of big but not very. Due to the amount of control in Vintage, two card combo wins aren't all that great, especially when they're not instant speed win conditions (Flash - which, while popular, is surprisingly unsuccessful in Vintage)). In reality it's a cheaper version of Grind-Servant which is good but never stands alone in a successful deck. The only other cool thing I suppose is that Key has some good interaction with a lot Vintage cards.
The biggest deal is that it an go off first turn, but the threat of forces make it unlikely that most players will want to risk their end game pieces that easily. In reality most vintage decks do not go off first, second, or third turn and are a fight of attrition against the opponents control.
My thoughts? You'll see it. You'll definitely see it but you won't see a deck based around it. It's a powerful backup win condition that, under the right situations, can sneak in a quick win. Id be very surprised if it actually blew up vintage as we know it or anything or if it'll even have a significient impact on the meta game (since theres already plenty of artifact combo hate in vintage decks).
