A source of a site called Making Star Wars, has said that a standalone film for Obi-Wan Kenobi, is in the works.
The source goes on to say: “I’ve heard from quite a few people now that an Obi-Wan Kenobi movie is in the works. For the spin-off movies they were initially going to stay away from any Jedi or Sith characters. But I’m hearing now that because of the popularity of Obi-Wan (fans recently voting for him on the official website etc) that an art team is now working with a writer on concepts for an Obi-Wan movie.”
The site mentions that this source, is the same source that gave out the first report that Luke Skywalker has been missing for 10 years.
As of right now this is just a rumor. However, I do think that Obi-Wan would be a great character that Disney could base a whole film around. Particularly, on the years after Revenge of the Sith and before A New Hope, since we obviously know how he became the master Jedi, thanks to the prequels.
Around this time last year, actor Ewan McGregor, who played the younger Obi-Wan in the prequels, had expressed interest to reprise the role.
The Making Star Wars article also talks about details for the upcoming episode VII.
Sources: Making Star Wars, E!