Challenge showed off some new cyclocross tires due out in mid-June, at their Sea Otter Classic tent. They're switching to a 300tpi casing across the entire tubular lineup. Making the transition to the entire lineup allows Challenge to offer their customers the new casing in several depths and patterns. Challenge will also be taking the existing Fango tread, and making it 3.2mm deep, which they claim will make it more of a fully studded tire to give it some depth to help with the clearing factor of the mud.
Challenge is also excited about the new Limus tire they'll be releasing later this year as well. We'll have more pictures of it as production ramps up.