If you're a fan of Anna Paquin, first the bad news: the one and only sequence she shot for X-Men: Days of Future Past has been confirmed cut from the movie. I don't doubt it'll surface in some form eventually, like the Krypton sequence Bryan Singer cut from Superman Returns, but for now, at least, the sequel will not be going Rogue.
In better news for Marvel fans in general, HYDRA leader Baron Von Strucker (seen in toy form above) will be a villain in the second Avengers movie. HitFix reports he'll be the initial threat who ties in Quicksilver and Scarlet Witch, while ComicBookMovie suggests that Dougray Scott, who was the original choice for Wolverine, may be in the running to play him. Scott had to bow out of the role that set Hugh Jackman for life when Mission Impossible 2 went long, and now he probably throws darts at a picture of Tom Cruise every single night. So he's kind of a perfect Marvel villain in real life.
Also, Marvel finally confirmed Paul Rudd as Ant-Man. I have no strong feelings about that whatsoever.