First off, this has zero to do with any realignment rumors. We're dealing with 2012, not 2013, not 2014 and/or beyond.
Two things are important with early season scheduling for television. By the way, for comparison purposes here's the 2012 and 2011 ACC contract's television appearances
1) Quality of opponents - In the ACC's case in 2012, there are not many appealing games ACC home games early in the year and less overall games available. Last year ESPN's TV networks picked up seven ACC home games over the 1st three weeks. Two were conference games and four others were matchups between teams in AQ conferences. This isn't just a trend for ESPN. The Raycom over-the-air and cable packages took three games involving FCS teams early in 2012, one more than they did in 2011 to begin the year.
It didn't help that Florida St. lost West Virginia as a home game late in the offseason and was unable to replace it with a comparable opponent. ESPN3 has 11 ACC games to start the year, nine against FCS competition. 2011 it was nine games with eight of those games against FCS schools, so that's rather flat to me.
Overall, the ACC has 22 available home games over the 1st three weeks. 2011 had 25 available home games.
2) Other conferences - The SEC's addition of Texas A&M and Missouri means that they'll have additional games available for TV throughout the year. The Pac-12 now has 20 games yearly available to ESPN's television networks. Even though most will be in primetime, available matchups will affect how other conferences are scheduled.
What didn't change?
- No new networks to fit in all the games
- Still only 24 hours in a day and teams don't like to kickoff before 12pm locally if they can avoid it.
Time and available space never changes when a conference expands or a network takes on more games without adding a new network or available day of the week to televise on.