TES VI is a certainty almost. It's their flagship franchise and the thing that put them on the map. I don't think we'll see the sequel until 2018 at the earliest, but to say they might stop here is just being illogically pessimistic, in my opinion. I've noticed most fan forums I've gone on for videogames has always assumed an end each iteration. Even Pokemon, back in 2007ish.
My guess for their 3 projects are TES VI, the TES card game, and maybe FO5 or a mobile TES game that is akin to Fallout Shelter. I could see the mobile TES game launching late this year or early next year, and could perhaps be a ploy to get a similar "4 billion sessions" to introduce new people to TES.