The collision resolution might get a radically new solution.
I guess most people ever use 2 or 3 actions only in their life, different sets of 2-3-4 actions.
If the actions were customizable (add/delete/edit) and allowed for flexible (regex?!) definitions (with appropriate variables at hand, for dates etc.), combined with in-place rename of the new (or old) file, most people would just remove the unnecessary (for them) actions and leave/define only the ones they need. Then they could have the choice to use them as buttons for one click action.
I think this would make the custom copy feature drastically more useful. I really find the current resolution dialog confusing and hard to use with the dropdown and buttons layout, especially when I only use Overwrite and Keep Both Files (Suffix ... in XY's case) and have to find and switch between either choice from the many options almost every time - I never use the other options and they confuse me by adding clutter when I have to select one of 'my' two.
I wouldn't mind functionality over aesthetics
(if both cannot coexist in a given layout).
For now I'm switching back to Windows 7 copy because it's easier for now, and telling the truth I can't think of something that I'll miss - except for the fact I always tend to expand the Windows copy progress to see the speed which is a pain. I liked Custom Copy for its always-on copy speed on display.
To sum up - this is not a critical feature or change, but those were my arguments how this Custom copy feature could get a considerable usefulness boost.
Another change could be the annoyong popping up of the copy dialog - the Windows way is to never show this dialog for fast operations (on small files or fast disks) - if the copy/move operation takes more than one second (or so), only then the progress window is shown. With Custom copy if I copy 10 byte file, the dialog flashes for an instant which is not helping (if it isn't set to persist after finishing). Again - not a real complaint but idea for improvement.
Edit: I like Filehero's layout in the case when no custom actions definitions would be implemented.
Having only Overwrite as a new button will be almost pointless for many people who switch often between 2 or 3 actions - one time they will hit the Overwrite button, the next time they'll have to use the dropdown to choose the other option anyway - not very friendly/consistent.