MacRumors speculates on the possibility of Apple releasing updated Cinema displays at next year's Macworld Expo. According to the post, the new displays could incorporate the LED backlight technology that Apple has started building into their 15" MacBook Pros.
MacRumors notes that LED backlit displays going into the 30" range tend to be more expensive than Apple's current 30" Cinema display. However, if this is true, it would be a nice change from Apple's 2004 design of the current Cinema displays. There is no word yet on if the new displays would include the iSight camera.