Attendance is actually up compared to last year at this point. That is impressive because, Detroit is not at there usual 20,000 mark, they are at 17,000+ and Colorado is still below there usual, both good markets. Chicago can help really boost if they keep it up, cause their arena holds 22,000. Not that they will get that, but 17-18 thousand is not out of the norm.
And to the original poster..Nassau Coliseum only holds 16,234 people. If the Isles can average about 15,000 this year that will be close to 95% capacity which is pretty good.
Here are the numbers
ESPN - NHL Attendance Leaders - National Hockey League