Fascinating article on this topic from Nate Silver over 1 year ago in NY Times:
http://fivethirtyeight.blogs.nytimes.com/2013/05/31/why-cant-canada-win-the-stanley-cup/?_php=true&_type=blogs&_r=0
The summary of where he thinks the NHL could profitably expand are (in priority order):
1) Toronto (2 additional teams)
2) Montreal (additional team)
3) Vancouver (additional team)
4) Quebec City
In other words, Canada.
Plenty of things to potentially pick at in the analysis but it certainly makes interesting points too.
Las Vegas certainly looks like a bad idea. Seattle is a lot more viable than Vegas but still not a great idea unless you get some of the potential Vancouver 2nd team fans in the process (since a 2nd team in Vancouver isn't going to happen).
