Incase has posted a couple of teaser shots in their gallery of a new bag on the way, the Ripstop Backpack. Available in July from Apple, this bag looks to be a full-sized backpack that can carry more than just an Apple portable, a magazine and a pack of gum (I kid - I'm a big fan of Incase's stuff). I have also heard they have a new, fully-featured site coming later this summer which should help to settle the Incase + Apple conspiracy theories.
Pricing and specs of the Ripstop Backpack are still to be announced.
Apple MacBook Pro 15-inch with Retina Display (mid 2014)