ipython/ipython — pull request #2572 by dwf (2012-11-12 22:43:34+00:00)
Title: Make 'Paste Above' the default paste behavior.

Destructive paste mapped to Ctrl-M V is a surprising choice given that there was no drag-to-select on the area being replaced (there is a weaker notion of "selected cell" but this does not map to will-be-replaced-
by-paste in the minds of participants in an unscientific poll at PyConCA).

Destructive paste is still available as the last paste option in the Edit menu, qualified as "Paste Cell Replace".