> Closing this issue as I, personally, don't see this happening and there's no point in keeping it open.

Actually, Andrew and I changed our opinion on this, so I'm re-opening the issue.

After visiting three conferences this summer and talking to asyncio users, it seems that this is a very serious pitfall.  At least 8 different people shared stories about really hard to debug problems caused by "except Exception" code blocking cancellation.

I now think we should fix this and make CancelledError a BaseException.  Doing that isn't as straightforward as it seems as we have to first fix how asyncio handles BaseExceptions (my next ToDo).