1) What is this about Dolores Umbridge opening the locket, and "becoming possessed?" You become possessed when you open the horcruxes? I guess that happened to Ginny when she opened Tom Riddle's diary.
2) What about that music box that was in the cabinet with the locket? Is that a Horcrux too? The locket was a Slytherin thing, like the cup is a Hufflepuff symbol, the sword is Gryffindor, and the Ravenclaw horcrux is...what? Has that been said yet?
Okay that's really three questions.