I'm really looking forward to this filler a lot. I think Fu will be killed in this arc because Deidara stated that 2 jinchurikis were already killed before Gaara. (Chp. 266) I assume it would be Fu and Han. Gaara by Deidara, Yugito by Hidan, Sanbi by Deidara, Roshi by Kisame, and Utakata by Pain.
I think it would be great if Sasori is the one who defeat Fu, we never really see Sasori defeat a Jinchuriki level character. Konan would be awesome too because the theory of the Second Animal Path coming in chuunin exam that could be a spy for her to bring in Fu. Pain is also ok I guess, but it will take a lot of fun from the filler because Utakata defeated in minutes.. Kisame is impossible because the seiyuu is dead and they'd not choose other seiyuu for some reason.. (Storm Games moveset for Kisame have been the same..)