I would love for the tasks with the same tags to be in categories. You could have the choice to view by tag or by list (or have lists of the tasks with the same tags). I'll give an example:

I add to my homework list "Math page 231-234 #1-7" "Read Monte-Cristo" (and add the tags "school, weekly") and to my personal list "Clean my room" (and add the tag "cleaning, weekly") .

Now, when I come back, I have the ability to view all tasks with the weekly tag, or my monthly tag, whatever the list they are tied to.