With the NHLPA agreeing to realignment, it's now up to the NHL to actually approve it and for it all to actually go into effect for the 2013-14 season. As the NHLPA stated, it'll be a two-year starter to be re-evaluated; which could also be the timeline to see if expansion could be a viable option for the league. While the realignment will bring about uneven conferences (16 in the East, 14 in the West), there are many more positives than negatives to come out of it.
First, this could have saved the Columbus Blue Jackets. They are a team who have been floundering in the West for years, and while they have been marginally better against Eastern teams (83-76-28 as per Aaron Portzline's Twitter); the travelling for the Jackets will be less strenuous (on the team and the finances), the fans of visiting teams will be more available to travel to Columbus with Detroit, Toronto, Pittsburgh, and Buffalo within a somewhat reasonable drive for a road trip-- albeit somewhat longer than usual, it's a fun drive (from Baltimore it was, at least), and it could give the Blue Jackets a puncher's chance of being in the top three of the division or getting one of the Wild Card spots.
That's the second one, the playoff format will bring more of a revenue stream to the NHL, helping the financial health of the league. Basically, in both conferences-- the top three in their division will be in the playoffs and the other spots to "Wild Card" team, which will also bring back the divisional play-out to get to the Conference finals. The Wild Card teams will be the two best records in the conference who don't have a playoff spot and the worst record Wild Card team will play the top record Division team. Many loved the old-school model of Divisional play meaning something-- for more than just being the top in the Division in order to get a top-three seed in the playoffs.
A final one for me is the regionality of it all....minus the Florida teams who really get hooped in all of this. Yet, aside from the rest of that division having a tractor beam bring up the Florida teams, all of the other teams are regionally based, which will create an increased rivalry for most teams. Granted, while most teams in the old Northeast Division are intact, teams like the Red Wings will join that fray; plus the Caps are back in the old Patrick Division, which is where most of their hatred for the Pens and Flyers first sparked up. Though, many in the West are as spread out as always, they have a little bit more condensing, though the Red Wings leave the Blackhawks out to dry in terms of the rivalry deal.
Overall and obviously, this is a good thing for the game. It brings some rivals back together, maybe creates some new ones, and only really breaks up one big-time Original Six rivalry. As well, it leaves the Expansion Card to be used to even out the conferences, though they'll have to realign again if there are not two Western markets to compensate-- especially since Seattle is the only real legitimate West Coast market that has been teasing the thought of a team. This experiment will get two years, but here's to the hope that it continues beyond that.