We’re less than 24 hours away from Apple’s “Rock and roll” event, an invitation-only press session in San Francisco Wednesday that’s expected to focus solely on Apple’s music-related products.

As always when there’s an Apple event, Macworld will be there in full-force. Look for our live coverage of Wednesday’s event to start at 10 a.m. PT, with reports, pictures, and even tweets from the Yerba Buena Center for the Arts Theater.

But what will those reports, pictures, and tweets reveal? Or to put it another way, what does Apple have in store for us at this year’s edition of its annual fall music event?

As Christopher Breen wrote last week, ’tis the season for new iPods. Apple traditionally refreshes its iPod lineup in September to get ready for the holiday shopping season. In September 2008, Apple introduced a new iPod nano, made changes to the iPod touch and pared the iPod classic to a single offering.

September 2007 saw the debut of the iPod touch and the rebranding of the full-sized iPod as the iPod classic. And September 2006 brought lower prices, brighter displays, and enhanced battery life to iPods. You get the idea.This time around, Apple is rumored to be adding cameras to its iPod classic and touch models. Whether that’s a good idea or not is an interesting question, but it would add a new dimension to Apple’s media players. However, some reports claim that Apple has had technical problems during testing and may not release such products on Wednesday.