I've not read Anne McCaffrey's Pern books. I have friends who have, though, and they love them. The world is a rich, exotic environment, the varieties of dragons are many, and I could see an AVATAR-like film being made from these stories. Now, according to Deadline, X-MEN and WATCHMEN scribe David Hayter has been hired on to adapt the first novel of the series, DRAGONFLIGHT, for Copperheart Entertainment, Dark Hero Studios, and Don Murphy and Susan Montford.
The Pern series is long - 22 books - and McCaffrey's work has been around for many years. There's a ton of source material to go through and since dragons seem to be back in vogue, or at least going to be, with THE HOBBIT coming, I could see these series of films becoming immensely popular. I could also see these films costing a staggering amount of money, as they would be extremely effects-intensive.
If dragons are coming back in a big way, I hope the Temeraire series by Naomi Novik gets adapted as well. Last I heard, Peter Jackson still had the rights to those. Those books are great, and giant naval battles crossed with swarms of dragons above, to me, equals awesome. I think I might have to finally dive into Pern as well - it's one of those fantasy series that everyone's heard of, and held in very high regard.