Between Airlie Beach and Rockhampton there wasn't much as far as I remember but a little further south you find a couple of good options. I once spent christmas at Agnes Water/Town of 1770, a picturesque little village by the ocean. There's no big night club scene, but a few nice pubs and you can do trips to less touristy parts of the Great Barrier Reef (Diving at Lady Musgrove Island was amazing). I remember we had surfing lessons the day before christmas and a huge barbie on the beach on christmas day with lots of other backpackers. Also the hostel we stayed at, called Cool Bananas was a great and friendly place who even had a christmas roast for their backpackers!
Alternatively, you could spend christmas in Noosa. It also a really pretty place, a bit livelier and more touristy than Agnes Water, but nonetheless one of my favourite places on the east coast. The YHA is a good option to stay at and definitely do the coastal walk, you're likely to see Koalas!
Steff