Getting to the horcrux of the matter -- Dan Froomkin notes that someone using an IP adress in eop.gov (the White House) edited the wikipedia entry on horcruxes. I too have made guesses about possible horcruxes right here.
Quite frankly, I think I did better than whoever was at the EOP (big surprise eh).
Details and spoilers below
comparing my predictions to the White House edited Wikipedia I note two differences.
I correctly predicted that Mundungus Fletcher stole the Slytherin locket from 12 Gimauld place.
I was confident that Harry is a Horcrux.
I know the definition of a horcrux, can count and assumed that 7 pieces of Voldemort's soul implying 6 horcruxes was true so there was know Ravenclaw or Gryffendor horcrux.
I'd say my predictions stand up very well. I count 9 correct predictions and 3 errors (some only hinted).
Sad to say only one poll per post, so you will have to correct me in comments.