Well, this is still nowhere close to being finished, but I have the main interior made out. This was done without MCEdit or any other mods, just regular creative mode. Assuming 1 block = 1m, the rink at least is accurate to NHL standards, not international. I needed to scale down the seats for aesthetic purposes, and if 1 block is 1 seat, this would probably seat around 5-10 thousand people, judging by some (very) rough estimates. I chose to use wool rather than ice simply because ice ends up being blue, whereas an NHL rink by appearance is white, rather than blue.

Minecraft Forum Thread (I might update there more often): http://www.minecraftforum.net/topic/684689-nhl-arena-wip/

Future Updates:
-exterior
-interior details (hallways, concessions, staff area, finish change rooms, etc)
-jumbotron (something looks wrong with it, trying to put my finger on it)
-ceiling
-alternative method of lighting, if possible