If you thought the world of Mergers & Acquisitions was hard to follow in the library systems marketplace, well buckle up for content providers. The Thomson Corporation has sold off its assets in Thomson Learning to Apax Partners and OMERS Capital Partners, for a total of about $7.75 billion in cash. (I love seeing “in cash.” . . . “Hey, can you break a trillion? I left my billions in my other wallet.”) The transaction includes Thomson Gale, Wadsworth, Delmar Learning, Brooks/Cole, and South-Western, and comes as no surprise since the intent was announced last fall. Details of the plan …