Apparently, the news was released when Sitch filed legal docs for his ongoing lawsuit against Abercrombie & Fitch for introducing a line of "GTL-inspired" clothes without paying him royalties. In the documents, Sitch asks the judge if he can skip the impending court date, which is set for June 14th, because he's required to film Jersey Shore between May 22 and July 7th. Skipping, he claims, would violate his contract.
So, there you have it. Looks like the whole gang will be back.