I don't want to do this for a few reasons. For one thing, we don't directly store the data per-resource, just the edit timestamps. I wouldn't want us too, it's a bit bloaty. We can pull it from the action-logs, but that's a performance hit. Another reason is that I don't think it is generally useful. The date kind of tells you when it was last reviewed, but a username tells you little as it may have been edited by multiple people in a short space of time, so you don't really know who really looked at it and by how much. Finally, I think it's a potentially privacy issue, or at least it's not consistent if people would want this or not - so to do it right we'd have to have 'mark as edited' and 'show editor name' fields for each resource type too. It'd get very messy fast.
(Click to enlarge)
#2457 - Include username on edited details
#2119 is a better solution.