When you have 2000 rep, to retag a question you have to click "edit", scroll down, change the tags field, and press save changes. It would be much easier if we just did retags asynchronous instead of by loading a new page. You hit retag, the list of the question's tags pops up on the same page, you edit, and press save (like how posting comments works). We would still have an edit button that takes you to a new page with full editing features for 2000 reppers (with the retag editing still there of course), but next to it a retag button for quick retagging of questions. Retag is probably the most common edit to a question, so streamlining it makes sense.
(I know I've seen this discusses elsewhere, but I can't find it. The other question said something about allowing you to edit a question's tags without even opening the question, but I think that's a different matter and would be better discussed in a separate question)