Available only through the Mac App Store (July) and weighing in at a mere 4GB, Lion will be the easiest update ever, Schiller says. Oh, and it only costs $29.99.

(Credit: CNET Staff)

Updated at 12 p.m. With this page on Apple's Web site, we were able to confirm that Leopard users must upgrade to Snow Leopard before Lion.

A round of applause (among many) filled the room at WWDC this Monday when Apple's Phil Schiller announced that the next operating system, Lion, would be priced at a modest $29.

"I was hoping you were going to like that," Schiller said after giving the price tag and July release date.

Although developers rejoiced at the disc-free 4GB upgrade, the reality for current Leopard users is sinking in: Lion will only be available for download in the Mac App Store.

Those currently running Leopard must first upgrade to Snow Leopard ($29) to gain access to the App Store, through which they can purchase Lion. Price at checkout: $60.

It's not unusual for companies like Apple to prohibit users from skipping software upgrades; Apple previously required those running Tiger to purchase Leopard before moving onto Snow Leopard. Some users have been able to leapfrog upgrades in the past (which violated the TOS), but with the new, disc-free upgrade, Leopard users seemingly have no choice.

Needless to say, many users aren't happy. Here's what they're saying on Twitter.