Toei has set up an official blog and twitter for the upcoming V Cinema movies of Kamen Rider W. They haven’t revealed any major plot points regarding the two movies.
However, they have posted some pictures and minor details regarding the 2 movies. Toei gave three keywords to describe the two movies in an attempt of keeping Phillip’s research theme.

Accel:
“Overkill Cop”
“Nonstop Action”
“Love factor”

The one who came up with the idea of making a spin off for Accel was Hideaki Tsukada, the producer of Kamen Rider W. He told his supervisors that he wanted to create a new show called “Kamen Rider Accel”, it eventually led to a V Cinema. Accel’s movie will retain the same Kamen Rider W theme, but it will be slightly different. There will be no detective and client, but Terui Ryu will have to work together with a girl who got herself involved with some case and they’ll have to prove their innocence together. The blog states that it will work in a similar way as it did in the TV series.
Terui Ryu will also have some fights without transforming into Accel. Kinomoto was very happy to do all of his own stunts and do some fighting out of suit. Our beloved main characters, Shotaro Hidari and Phillip, are set to appear in the movie. However, they are only there for support and might not even transform into Double. Accel’s movie will also feature his own opening, it’s currently not confirmed whether it’s a new song or if it’s going to be Leave All Behind.

Eternal:
“Military history”
“Evil VS Evil”
“(Eternal’s)Begins Night”

Eternal’s movie is going to be significantly different from the Kamen Rider W TV series. Kamen Rider W that had a detective theme will have absolutely nothing to do with Eternal’s movie. Instead it will focus more on fights and war battles. Eternal’s movie will have a similar feel to Cyborg 009. It’s also confirmed who is going to do the theme song of Eternal’s movie. It’s going to be Matsuoka Mitsuru’s band “SOPHIA”. Koichi Sakamoto who directed Kamen Rider W Forever is back to direct the action scenes of Kamen Rider W. Hopefully we’ll get some action-filled fight scenes just as good as they were in Kamen Rider W Forever.

The latest tweet also says that both of the movies will be 70 minutes each, a trailer that shows actual footage will be available February.