Yes, in 2008 Naho Ooishi made a manga adaption for Akira Toriyama's DBZ special "Yo son goku and friends return", and it was pretty good.
He said in an interview that she knows dragonball very well, and over the years he has forgotten a bit of the story, so what better than to let a fan take over. He is not even doing one shot mangas like he used to, he is getting older and wants to enjoy his life. Dragonball Hoshi is supposedly going to be a manga CONTINUATION of the Dragonball Z manga where it left off with goku training uub. There will be an anime adaption as well. A newly designed ssj4 and more powerful version has been mentioned, and even a ssj5, both by Naho and Mr. Toriyama. This project was on hold for the efforts to help Japan in their time of need. Mr. Toriyama will help her out with the first arc, then slowly back off and let Ooishi take over.
If this project goes in fruition, then this will be added to the "canon" storyline along with dragonall/z/ online, remember gt is not a manga, nor is Z Ultimate, so those would be considered "what if" alternate universes. while at this, since toyble made a respectable online doujinshi about the fanmade AF series, that could be considered an "alternate timeline".
Non Canon Doujin- Dragonball H, Dragonball AF (in my eyes, Dragonball H is cannon everyone knows it is)
Non Public (developer's only series) - Dragonball Z Ultimate (4th series)
Limited Edition (poorly advertised) - GT Specials (as it takes more money to make movies)
And so there you have it.
Other than this there may be more crossovers to look forward to, and of course games but i dont keep up with the games because i am continuously convinced they are the same thing over and over again.