Sorry for the bump. Looks like the project has been put on the backburner:
Michael Dorn said:
"Last year, there was interest and I talked to a couple producers, and we actually had [a] pitch meeting with Paramount and CBS," Dorn said. So why haven't we heard more about this Worf series before now? "Business things got in the way in terms of the J.J. Abrams movie coming out and CBS/Paramount and their relationship with J.J. Abrams," he explained. "I don't think they wanted to step on his toes by putting a new series on, but it's not dead yet."
That article is dated 21 August 2013. In other words, even though Dorn says the project is "not dead yet," it basically is for the foreseeable future.
Also: Frakes has been joking around about "Rikers in Space" since at least when Voyager was in development; From what I recall, he (perhaps jokingly?) suggested that it be Riker and Troi who were stranded in the Delta Quadrant. Thankfully, Paramount didn't go for it.