In just two days, Pitt will officially become an ACC member and head to the Coastal Division alongside Duke, Georgia Tech, Miami, North Carolina, Virginia, and Virginia Tech. The Coastal is the perceived weaker of the two divisions, as Virginia Tech, the lone big name program in the division, suffered a surprisingly down season while the Atlantic Division has Florida State and Clemson, two schools that can challenge for a national championship this season.
But despite how much stronger the Atlantic looks, the divisions are actually fairly equal historically. The Atlantic Division is just 79-73 against the Coastal since the conference split into two divisions in 2005 and, had Georgia Tech not had to vacate it's 2009 ACC Championship, the two divisions would be 4-4 in the ACC Championship Game.
Every program goes through cycles and Florida State and Clemson are far and away the best two teams in the conference. But not long ago, they were struggling to 6-6 seasons. Miami, Georgia Tech, and North Carolina are all trending upwards. For people that want to realign the ACC divisions, there isn't any reason to, except to make things a bit more geographically aligned. But that would likely fill one division with the big name schools while weakening the other. For now, there is no reason to realign the divisions. They're both fairly equal, despite what it appears initially. Who knows how things will be in a few years though.
If the ACC were to realign, many options thrown out have been a North-South or an ACC-Big East alignment. I prefer the latter, as it keeps yearly games with Syracuse and Louisville while adding in Miami, Virginia Tech, and Boston College. Plus the old folks in the ACC would like to see all four North Carolina schools play each other yearly, which won't happen under the current alignment.