Last year was pretty much the perfect storm
the higher-ranked, 11-1 Va Tech Hokies were upset in the ACC championship game, giving the automatic BCS bid to 9-3 Clemson.
the SEC placed 2 teams in the BCS national championship game, which meant that the Sugar bowl needed 2 at-large teams instead of just one.
Houston lost the C-USA championship to Southern Mississippi, which meant that no non-AQ team would have to be selected as a BCS at-large.
Without all 3 of those elements, the ACC probably would still be waiting on its first at-large bid. However, now that the conference has had one, can it get another?