A few weeks ago on Phat Loot Phriday, I wrote about the Essence of Eranikus, a cool little trinket from the dragon in Sunken Temple. It's actually part of an unfinished questline-- a few steps after you get the gem from Eranikus, the questline ends in Winterspring with no explanation as to what happened with the rest of the story. Like many players (including myself), Falandan wants to know if Blizzard has any plans to finish up this series of quests.
Tseric answers on the forums, and says that while Blizz is leaving their option open, the main problem with returning to unfinished quests (The Missing Diplomat/King of Stormwind is another) is that they'd have players of a high level doing low level quests. Either that, or they'd have to interrupt the normal leveling game, and you'd be doing quests in the same line with ten (or more) levels between them.