According to TMZ, the next the spin-off movie in the Star Wars franchise will indeed focus on Obi-Wan Kenobi.
The gossip website claims to have obtained a leaked document from Lucasfilm with the codename Joshua Tree which includes this brief synopsis:
“Obi-Wan is on Tatooine being an elusive hermit and stuff, but secretly watches over an infant Luke Skywalker, whom he delivered to his uncle, Owen. Tensions between the local farmers and a tribe of Sand People — headed by a ruthless war chief — eventually brings Obi outta hiding … and into Jedi kickass mode.”
The document also lists Stephen Daldry as the director, that tidbit seems to support the rumor that he was in talks to helm some part of the Star Wars saga. No word yet if Ewan McGregor would reprise the role he made his own in the prequel trilogy for this movie but it would be a darn shame if he didn’t.