First up, Vulture has some character confirmations.
We all knew (or at least highly speculated) that Peter Dinklage was playing Bolivar Trask, creator of the Sentinels. Vulture has now confirmed this.
The other character is one we didn't know about, and that is who Josh Helman is playing: William Stryker.
This makes Helman the third actor to play the character. In X2: X-Men United Bryan Cox played him and in X-Men Origins: Wolverine Danny Huston filled the shoes. Since DoFP takes place roughly ten years before Origins, it makes sense for him to be younger.
Next we have new pic from the set courtesy of Bryan Singer, and it's of a familair face from X-Men: First Class:
Yes, Lucas Till is back as Alex "Havoc" Summers.
Here's the caption Singer tweeted with the shot:
"Mankind must put an end to war before war puts an end to mankind." -JFK
Last we have a description of what the plot of the film will be. As we know from the title it will be based in part on Chris Claremont's Days of Future Past story line.
Here's what Vulture has on Singer's adaptation:
In Singer's take, Ellen Page returns as Kitty from the Brett Ratner–directed X-Men: The Last Stand, but this time she uses her powers to send Hugh Jackman's Wolverine back into the past, where he encounters the younger mutants played by James McAvoy, Jennifer Lawrence, and Michael Fassbender. However, something bad happens to Kitty during the time-travel trance, and while Wolverine is still under her spell, the other X-Men must race to find a mutant who can siphon Kitty's powers and bring their friend back to the future.
As Vulture posits, it's a safe bet this is where Rogue make her self useful.
X-Men: Days of Future Past hits theatres May 23, 2014.