Hi @teppokoivula - I think it would be very handy to have the revision popup available from the history tab for each field. When you have a template with lots of fields with version control enabled, it can be very useful to look at the history tab to see what has actually changed, and accessing the diffs from here would make it even more useful, I think.
Mostly OT, but I would also like to see a close "X" on the popup - I find some users struggle to close it, not realizing they need to click the same icon again.