Hi Daniel,
Like you, my family are Walt Disney World veterans who had never visited for New Year's Eve - until last year! Disney has not yet released details of special celebrations for New Year's Eve 2014 and New Year's Day 2015, but we can look to last year for some thoughts on what might occur.
Our family chose to spend New Year's Eve at Disney's Hollywood Studios. We had an absolutely wonderful time. We arrived early - around mid-afternoon - and spent most of the afternoon and evening taking in the attractions. By about 11:00 p.m., we headed over toward the Sorcerer Hat, where a huge stage was set up and Mulch, Sweat & Shears had been playing sets through night. Though we could not get right up front at that time, we could still see the stage. Fireworks rung in the new year at midnight. It was a high-energy and fun time. It was crowded, and it did take a while to get out of the park and back to our resort after midnight, but that is to be expected.
Of course there are many other celebrations around Walt Disney World on New Year's Eve. Last year, DisneyQuest Interactive Indoor Theme Park hosted a party with character greetings and refreshments. Epcot offered a special viewing of Illuminations: Reflections of Earth and special New Year's Eve fireworks, and Magic Kingdom Park offered special fireworks at midnight. I suggest that wherever you want to celebrate, that you get there early as the parks are quite crowded at this time of year. Disney does sometimes offer special dining experiences on New Year's Eve. I suggest that you keep an eye on the
Disney Parks Blog for announcements regarding New Year's Eve activities.
I would love to help you plan further Daniel; however, I am limited in the space that I have to answer. Please do write back if you have any further questions!