It is still technically possible.

Imagine this scenario:
Missouri, Virginia Tech, LSU, USC, Hawaii, Arizona, and Oregon State all win big on Saturday.

BYU would then be #13 or #14 in the final standings. There would be guaranteed BCS bids for Missouri, VT, LSU, USC, Hawaii, West Virginia, and Ohio State. Georgia and Kansas would surely get chosen as at-large teams. That is 9 teams so far.

The final BCS spot would be an at-large selection by the Sugar Bowl. Their choices would be Clemson, Illinois, Wisconsin, and BYU.

What are the chances that BYU would be chosen in that case? Very, very, very small. But it is still not mathematically impossible.

BYU could become eligible for an at-large berth even if Hawaii got an automatic berth. If for some insane reason one of the bowls selecting at-large teams chooses BYU, we would be in. That is why I won't call it impossible. The Fiesta could technically choose BYU instead of Kansas as well. Of course it won't happen, but it is still possible.