Hollywood Reporter, Milk Visual Effects is going to be doing the VFX for series eight. The Mill reboot did jolly well with the effects for "The Day of the Doctor" ("For the special, Milk produced 129 3D VFX shots including CG environments, CG spacecrafts, and the sequences featuring the Gallifreyan city of Arcadia." And part of the UNIT-lowering-the-Doctor sequence, it seems.) So it's nice to hear that everything seems to be back on track for the team. They put up a fascinating behind-the-scenes feature here.
There's an interesting side point buried in the article: a line notes that "Milk is currently working with BBC to create the VFX for the one-hour Doctor Who Christmas special, "The Time of the Doctor," in which Matt Smith’s Doctor will regenerate into Capaldi’s incoming thirteenth Doctor." That kind of special-effects-finished-close-to-transmission is understandable when there's been a full series of DW to take care of, but it seems curious in a year with only two episodes.