Is Dragon Ball Super considered an original works by Akira Toriyama?
This really depends on what you consider canon, but for now let's define "canon" as material that's covered in the original source material and has impact on the story.
Since this season does have a manga adaptation and takes place after Kid Buu Saga from Dragon Ball Z but before the tournament with Uub, I would say that this is canon material.
But, After seeing more then the first episode I think its safe to say that the anime does not follow the manga 100%. Therefore I consider it somewhat canon.
Yes, it is. The stories for both the anime and manga versions of Dragon Ball Super are indeed written by Akira Toriyama.
In addition to his role as series creator, Akira Toriyama is also credited for the "original story & character design concepts" of the new anime directed by Kimitoshi Chioka.
The anime is being adapted into a companion manga by Toriyama alongside artist Toyotarō, author behind the official Resurrection 'F' manga adaptation. It began serialization in the August 2015 issue of V Jump, which was released on June 20.
This leaves open your title question whether the anime should be considered canon.
Here Madara Uchiha answered that filler equals not canon, while pieces written by the original author should be considered canon. Now the DBS anime is both, seeing how "Vegeta's day out" would be filler, yet is written by the original author.
Here ton.yeung answered that something should be considered canon when the material is borrowed from the original works. So if you would consider the manga as original work, than the anime would be filler, yet if you would consider Toriyama's mind as original work it would be canon.
Seeing how at this point it is rather messed up and confusing, my two cents would be that it will probably be considered filler (non canon) after a while. People would either forget (or don't care) the additional episodes were produced by Toriyama or would stick by the general rule that only the original works (aka the manga in this case) can be considered canon, despite the author of the anime. So, not sure if it is, but manga readers will probably consider all the extra content not to be canon, while anime watchers will probably not even know/care about the existence of the manga and unknowingly think everything that happened in the anime to be canon.
As much as i love super already... Technically Super is not cannon with Z either. Why? because it takes place straight after the buu fight (Between the 10 year time skip). Pan's not even born yet & Goku sure as hell had not activated god mode before the fight with Uub at the tournament (Last Episode Of Z). Completely parallel timeline. Although it does state it is on: http://dragonball.wikia.com/wiki/Dragon_Ball_timeline , however it also states GT is apart of the timeline aswell which many would argue is not. But still a series worth watching and cannot wait to see how it pans out!
Yes it is. Now here's something I didn't realize until I looked into it, if you want to get technical: DB Super, being written by Akira Toriyama, will actually be the ONLY dragon ball anime that IS canon. I'm Not sure why people think it isn't, they are all wrong.
Dragon ball, DBZ, and GT are technically NOT canon as Toriyama didn't write for them. They were based directly and heavily on his manga but he didn't write for those anime so they can't be considered canon per se. He has also called GT a "side story" so while most fans consider the first two animes MOSTLY canon (due to his influence) as he wasn't really TOO involved in GT (aside from some plot points and character design) most fans don't consider GT canon.
Super will actually be the only dragon ball anime that is canon.