Avatar making money is so great for so many reasons.
1) We get more Avatar
2) We get more James Cameron making whatever the fuck he wants
3) Other studios will look at the money Avatar is generating as a non-franchise, non-sequel, completely original film, and see that there is the potential for massive revenue in creating a new IP as opposed to solely working from one
4) The much-debated performance-capturing tech will have been proven exceptionally effective, both in terms of the actual visuals that result from it, and the ease and intuitiveness with which it makes directing a mix of CGI and live-action (though, obviously, not every director is James Cameron, and this point would also be proven if Avatar had made $0)
5) It will also prove, as a 2:40 hr long movie, that audiences are perfectly willing to wear 3D glasses for a movie that's worth it
Taken as a collective, Avatar will have advanced filmmaking, as was promised.
And also, greater recognition for awesome people like Sam Worthington and Zoe Saldana.