Ctrl+U and Ctrl+Shift+U for lower & upper-case are used in a few text editors I've seen. Maybe not standard (there isn't really a standard) but not uncommon.
Yes, there's no standard.. or better: There is, but there are so many! o) I'd always prefer the one used in the inline-rename.
That editor-control probably has it's own key-handling and "just" gets pulled-in? Does that explain the difference?
Anyway, I think DraggableDan is not off if he likes hotkeys to be the same throughout a single application and.. I must agree! o)