Grey's Anatomy was a good program about medicine and about relationships, but it has probably gone as far as it is going to go. All the relationships are resolving themselves one way or the other, and there are not too many more medical traumas or changes in personnel that can be done and still give the show coherence.
Grey's Anatomy has been airing for many seasons and many members of the original cast have moved on. Also, the show has lost much of its original viewership. It is customary for shows that have survived well past their prime to be canceled in the name of introducing new shows that can potentially garner new interest from audiences.
Yes, I believe that this season of Grey's Anatomy will likely be the last. I think that the show has had a great and long run and that the ratings are still pretty good for a show that has been on as long as it has been, but that it's about time to start wrapping things up.
Grey's Anatomy has been a surprisingly long lasting television series that has a huge fan base and draws in a massive television audience. Although shows like Breaking Bad quit despite these circumstances, those shows had reasons to end the plotline. Grey's Anatomy could easily draw out an interesting plot for a few more seasons.
The current season of Grey's Anatomy will not be the last. Grey's Anatomy is an excellent show and it has a lot of viewers. I do not see them ending it at this stage of the game but I fear that it will soon be wrapping up. It has been on a long time.