The biggest problem hockey has is the lack of scoring. The changes to open up the flow of the game were good and a big improvement. However, goalie equipment still makes it too hard to score. If you look at old footage, you see the goalies with pads but not the "mattresses" they wear now.
Back in the late 80's, early 90's Hockey was popular and growing. The reason was a lot of high scoring teams like Edmonton, Pittsburgh, Calgary, etc. Even people who don't understand all the strategy and rules can appreciate a goal and the excitement it causes.
The people who say get rid of hitting and fighting don't know what they are talking about. It is an inherent part of the sport, but more importantly people like violence. Everyone gets pumped up by a big hit in hockey just like they do in football. If anything, hockey needs MORE hitting and fights to draw tv ratings (see ultimate fighting).
Keep the violence, increase scoring and get on ESPN and hockey will be popular again