Rolling Stone Mag just a did a little article on how the economy will be affecting this years festivals. Not a lot of in depth info, or big revelations. But it does give some small info:

"Coachella Organizers have pledged not to sign high-cost headliners like 2008's Prince and Roger Waters. - "It was getting out of control, we're as price conscious as we have ever been".

"Similarly, all the top festivals, including Bonnaroo, Coachella and Lollapalooza will freeze prices at 2008 levels, according to promoters"
So basically, no high cost headliners (I think we can finally count out all Paul McCartney) - and ticket prices won't be lowered, and will prob stay the same as 2008 (altho Lolla is offering a new pay system).