Maybe I'm wrong, but I didn't feel that WTFs reply really cleared up the "money line" odds much. The -155 actually stands for how much money you have to wager to win $100. It works out the way WTF says, but in the interest of oversimplifying for a newbie, this works better. So when wagering opened, you had to risk $155 to win $100 (i.e. you pay $155 for the ticket, they pay you $255 if you win), but now, you have to risk $200 to win $100. (Obviously, you don't have to bet to win $100. You can bet any amount you want, but the payouts will be at this ratio.) The reason the number has increased is to incentivize future bettors to take the Islanders, since most of the early wagering has been on the Hurricanes, and the job of the sports book is to take in as close to the same amount of money on both sides.
It shouldn't be looked at as a prediction by the sports book, only that most of the betting to this point has been on the Hurricanes and they've had to jack the payout up by a very large margin to encourage betting on the Islanders.
IMO, anytime a hockey or baseball line gets to the 200-mark, the underdog is a good play. I'll automatically bet on any baseball, football or hockey underdog paying +250 or more (i.e. bet $100 to win $250).
UFC fighters who are huge favorites can go off at -800 to -1,000. Mike Tyson regularly went off as a -2,000 favorite (i.e. to win $100, you had to risk $2,000) until most sports books stopped taking bets on his fights. On the night he lost to Buster Douglas, Tyson was a 42-1 favorite (i.e. -4,200), but only one sports book was even taking bets.
