Apple has shocked fans with a brusque statement on its website  saying Steve Jobs will not appear in his usual keynote slot at January’s MacWorld Expo (Jobs’ slot will be taken by little-known VP Philip Schiller).

Further, January’s MacWorld will be the last time that Apple will support IDG’s iconic trade show.

MacWorld has run every year since 1985, moving from Boston to San Francisco, and become Jobs’ main – and often only – stage for presenting new products, always wearing his trademark black turtleneck sweater and jeans.

Jobs’ disappearance will surely spark new rumours about the Apple CEO’s health, and his future with the company he returned to save. During his last public appearance, at the Let’s Rock event during September, Jobs (53) looked painfully thin, sparking internet rumours about his health. Apple issued a statement saying the pancreatic cancer survivor was recovering from a simple bug (watch Apple’s video of Jobs’ Let’s Rock keynote here).

Adobe and Belkin already pulled out of the January 2009 MacWorld, with Google and others reducing the size of their stands.