Peter Jackson has said he will never make an epic fantasy film again because he has no wish to compete with himself, although he might produce one and would certainly be happy for WETA to take part and lend their expertise and experience (as is happening with The Hobbit movies). He is working on Temeraire as a TV series because whilst it has dragons, it also has the whole Napoleonic Wars angle, with gunpowder and cannons and so forth, which makes it a different challenge to LotR.
So, Jackson as the director of a potential Magician movie (or a WoT one or whatever) is right out of the question.
As for the chances of this happening, I believe Feist has said that it's almost happened a few times, as Magician is not only a high-profile book in the genre it's also comfortably stand-alone, so it doesn't leave people hanging on the sequel. It's also different enough to stand out from the crowd.
At the moment we have A Game of Thrones waiting for the first season commitment from HBO, The Lions of Al-Rassan (still) in development for Edward Zwick, The Elfstones of Shannara has come to a screeching halt due to Mike Newell deciding to do another project and The Eye of the World is still locked in development hell at Universal. On the plus side, The Hobbit is now deep in pre-production in New Zealand.
My guess is that if these projects move forward and some or all are big successes, Magician will be picked up at some point. If they aren't, it won't be. Based on the rather inconsistent performance of post-LotR epic fantasy movies, I'm guessing the current crop of in-development movies represent a 'last-gasp' for the genre this generation, and if they don't take off we won't see any more for some considerable time.
