Outside of the theme parks, most of the New Years events will be more nightlife-oriented than anything else, so considering that you have kids I am not sure if this is what you are looking for. Even though you mentioned you want to stay away from Disney, I highly recommend Epcot, the park will be open until 1am and they have a special New Years Countdown beginning at 11:40 that concludes with one of the largest firework displays that you will ever see in your life, out of all the Disney parks Epcot is the most adult-oriented as they will have live DJ dance parties and serve alcohol but you are still within the safety of Disney. Just keep in mind that anywhere you go will be extremely crowded so patience will be a must. Have Fun!
These are some of the things that I would like to do while in Orlando, maybe these will give you some ideas:Indoor Skydiving- http://www.skyventureorlando.com/Hot Air Ballooning: http://www.trustedtours.com/store/Hot-Air-Balloon-Ride-of-Orlando-C214.aspx?PID=3454578Airboat Rides: http://www.bcairboats.com/index.shtmlPaintball: http://www.orlandopaintball.com/final.html