I think the grand prix series of tournaments is one of the best systems FIDE has come up with in a long time. It's extremely rigorous, as results over a series of tournaments matter, but each individual tournament also seems to quite palatable to sponsors. It also manages to include a very large portion of the world's top players.
I would like to see much more weight given to the grand prix. Take the top 2 finishers of the grand prix, and have them play in a match of at least 8 games to decide the challenger to the champion. The top placed grand prix finisher should have draw odds, so never is a rapid game used to decide!
I think most prediction based on probability and ratings would likely yield the wrong result.
Here is why. I have to pick a popular sport. Say NBA, NFL, NHL or Major League Baseball. Can you predict who will be the champion of those sports for the year 2013/2014? I guess you only have less than 25% chance of naming a club that would become the champion of those sports.