I understand wanting to preserve some old rivalries, but having Boston in the Central Division and Columbus in the Atlantic makes absolutely no geographic sense when Columbus is well west of Boston. How is Boston not an Atlantic team? Boston is literally on the Atlantic.
I also don't like expanding the post-season to 20 participants. That means 2 out of 3 teams would make the playoffs. The regular season would be essentially worthless. I'd rather see some more minor tweaks made to the current format. Another problem is accommodating relocation and expansion. Realistically, there will be three new cities with teams in the next few years: one for the relocated Coyotes (probably Seattle), one for Quebec City (which is already building a new arena), and a third one for some other city (Kansas City? Hamilton?) in order to keep the number of teams in the league at an even number.
If we absolutely must have realignment, I'd like something as follows:
North Atlantic (5) - Boston, Buffalo, Montreal, Ottawa, Toronto.
Mid Atlantic (5) - New York, New York, New Jersey, Philadelphia, Pittsburgh.
Southeast (5) - Carolina, Florida, Nashville, Tampa Bay, Washington.
Mid Central (5) - Chicago, Columbus, Detroit, Minnesota, St. Louis.
Mountain (5) - Calgary, Edmonton, Seattle, Vancouver, Winnipeg.
Southwest (5) - Anaheim, Colorado, Dallas, Los Angeles, San Jose.
Each team plays 4 division rivals 8 times (4 home, 4 away) for a total of 32 games.
Each team plays 10 intra-conference rivals 4 times (2 home, 2 away) for a total of 40 games.
Each team plays 2 games against 5 cross-conference rivals (1 home, 1 away) from the same cross-conference division for a total of 10 games. These divisions rotate by year:
North Atlantic (EAST) vs. Mid Central (WEST)
Mid Atlantic (EAST) vs. Mountain (WEST)
Southeast (EAST) vs. Southwest (WEST)
North Atlantic (EAST) vs. Mountain (WEST)
Mid Atlantic (EAST) vs. Southwest (WEST)
Southeast (EAST) vs. Mid Central (WEST)
North Atlantic (EAST) vs. Southwest (WEST)
Mid Atlantic (EAST) vs. Mid Central (WEST)
Southeast (EAST) vs. Mountain (WEST)
The total number of games in a season remains at 82. Travel is significanly reduced. Schedules are identical for every team within the same division. There are still a limited number of cross-conference games (10 of the 82). Everybody is guaranteed to play everybody within a 3 year period.