The opportunity to rename on paste is needed, but even more needed is more info when there's a conflict, especially dates and file sizes. I've often felt I'm flying blind when copying files raises a conflict.
I think it was Limewire (scary o.o) that had the feature I loved. When you downloaded a file with the same name, it was Skip, Replace, or Append#, which was helpful on so many occasions. :D
You know, I actually wrote a really long message to the GNOME Usability mailing list about this. Nobody really seemed to listen to me there, but here's a link if you're interested:
Case-by-Case:
-comparing two files
-renaming possibly both files
-overwriting one file
-leaving the conflicted file at its source
Generalization:
-renaming files consistently (appending, prefixing, etc.)
-overwriting all files
-leaving all conflicted files at their sources
I also think the choose options as you go thing is dumb. It would be easier if you were compiled a list of source/dest files that conflict each other at the end of moving everything else, and given the opportunity to compare, rename, overwrite or leave a file at it's source.