Earlier this year, they were withdrawing their booth commitments at Macworld 2009. Other companies are also rumored to be .

Still, the company behind the Macworld conference--IDG World Expo, which is owned by the same parent company as PC World--promises that Adobe will still be involved in some demo sessions. The changes, it insists, are no cause for concern.

Apple announced Tuesday that it would with the annual Macworld Expo after this January's event.

The company also said that Apple Senior Vice President of Worldwide Product Marketing Phil Schiller and not Apple CEO Steve Jobs will deliver the opening keynote address for the 2009 San Francisco show in early January.

"Every year we see a certain percentage of exhibitors pull out of the event for their own business reasons," a statement from IDG World Expo says. "In this economic climate, it shouldn't be a surprise to see this. The important thing to understand is that Macworld Conference & Expo 2009 will be similar in size to last year's event, and attendees will continue to visit nearly 500 great Mac product vendors on our exhibit floors."