Problem: Vandalism takes lots of time to identify and revert.
Proposed solution: Being able to fight vandalism without leaving the page you are on; for example pressing diff brings a drop-down that will allow you to rollback/revert and see the diff view on the same page and being able to warn after rolling back without going to the user talk page. I often find edits that are not vandalism and I waste around 30 seconds finding it isn't vandalism and going back to recent changes.
