In the short term yes, i doubt cameron will allow Avatar to be released on the old 3D format, as it will make people think that is the current state of 3D technology, and will put people off(rather like channel 4's 3D night...it was crap).
I believe all Blu-ray players are 3D compatable, as is every sky+hd box, in 2010 the first 3DTV's will go on sale, by the time Avatar is out on Disk, you will be able to watch it at home in 3D, however you will probably need to fork out