Doctor M said:

Shouldn't you just wait for the missing 40 minutes to make it to disc? There's a good chance some of the undeveloped characters will be fluffed up.

According to Cameron, the extended cut of Avatar that's being released later this year would only have 6-7 minutes of new footage (not 40 minutes...):
http://latimesblogs.latimes.com/herocomplex/2010/04/james-cameron-talks-the-enironment-the-avatar-sequel-and-more.html

Personally, I didn't see 6 new minutes, no matter what it's content, as going to add anything really major to the story or allowing me to effectively "re-write" the film's plot (unlike what I could do with Episode 2: Attack of the Clones and it's deleted scenes), so I decided to go ahead and just do an fanedit with what footage that's available.