Big news in the midstream (pipelines and processing plants) world. Today, Energy Transfer Partners (ETP) announced they are merging with and buying Regency Energy Partners in a deal with a total value of $24.8 billion–$18 billion in stock and cash, and $6.8 billion in assumed Regency debts. You may recognize both names, as both companies are active in the Marcellus and Utica Shale…