There have been many changes to the Plaguelands over the years. If you haven’t been there in a while you might be very surprised. Many of the previous regular quests and repeatable quests have disappeared from the game. With new quests and quest chains replacing them. Many of the original repeatable quest turn-in chains have been removed. The quests requiring Bone Fragments, Crypt Fiend Parts, Dark Iron Scraps, and Savage Frond are now gone. Insignia of the Crusade and Insignia of the Dawn reputation turn-ins have also been removed.
Click this link to be taken to the wowhead.com comments section. Read the post written by Malgeras. He gives detailed step by step instructions for leveling reputation. He shows the quests you need to open the repeatable quests necessary to go from revered to exalted. The repeatable quests are Annals of the Silver Hand and Aberrations of Bone and are obtained from Fiona. Fortunately with the nerf to all Vanilla faction reputations you should be able to reach exalted in 1-3 hours, depending on your play time.