I don't think any fan of the job Peter Capaldi was doing is ready to say goodbye to him. I believe he has stated that the workload was getting to be a problem for him and he wanted to do other things. I wish he would stay longer, but we can't have that. I do hope that he will jump over to Big Finish relatively quickly. We have the ~75 years he was guarding the vault until Bill came around, loads of adventures alluded to with Clara, and I'm sure there were plenty of gaps this season.