I don't know exactly where that would be because some ratings systems like Sagarin have stopped using their BCS version of rankings and their current rankings incorporate things like Margin of Victory which the BCS didn't allow in their rankings.

However, there are a few BCS computer rankings that are still around and they have BYU in the following spots:

Colley: 3
Wolfe: 1
Massey BCS: 1
Anderson: TBD (his first ranking may come out tomorrow??)
Sagarin: 18 (but his ELO used for the BCS no longer exists)
Billingsley: 7 (though like Sagarin his current ratings aren't quite the same as his BCS)

I suspect we'd be much higher in Sagarin and Billingsley had they still used their BCS formulas, but the takeaway of this post is to say that while we are hovering just outside the top 10 in the human polls, the computer rankings would probably have us around 3rd or 4th, which may have been a big enough of a pull to jump us up to 8th or 9th in the rankings.