I don’t know if these features are already in the works, but I would really like for functionality to be the same for various aspects of Unreal (see below)
Dragging off of a pin with an
existing connection in the Material Editor
places a connected node in between the two
previously connected nodes (like it
does in the Blueprint Editor).
Creating a comment box in the Mat Ed
highlights the text so the comment
can be modified immediately
instead of clicked and then
In Mat Ed, right-clicking a value
creates a parameter with the
default value already assigned.
Creating a parameter also highlights
the name so that it can be
modified immediately without
Various graph editors should use the
same navigation system
(right-click vs middle-click).
Animation in Persona should use the
same playback controls as Matinee.
I also think that dragging off of a pin, and holding a hotkey, then releasing the mouse to create the connected node would be very useful (i.e. drag off of a pin, hold M, and release mouse to create a connected multiply node).
These are just some changes that I think would add to the overall flow and usability of the engine.