I find the process of recurring tagging too time consuming. Very often I have to apply the same set of tags to a related notes (eg., when I create a note related to the same project I need to add similar tags such as the year, project name, etc.)
I believe the following features will greatly simplified the process:
1) Introduction of a automatic tagging based on user-defined filters (such as Gmail does). Eg. whenever a note is created, a tag with the current year or month is added, or whenever a note has certain word in the title a tag is added
2) "tag templates". For example, being able to copy and paste a group of tags to another note.