Any chance we'll see this happen? Makes it a lot easier when I can see C4, F0, D#5, etc. when I look at the notes. Also, colors graduated on notes would also make it easier to write and spot problems. C=Red, D=Orange, E=Yellow following ROYGBIV, with the sharps and flats in between the colors.

Oh yes, note names in the bars like in Cubase or at least in Studio One V3 would make enhance the midi editing workflow a lot.
 
Different colors are already used for different velocity, but maybe better would be here some kind of a fill gap like in Studio One.
 
+1
 

Seems like a nice option to me...
 

Eww, no.    please make it optional if implemented.

It would be useful to be able to switch between the two display modes (i.e. colour by velocity vs colour by note) via a button.
 

REAP**R has it. I like it for creating a "chord" type track to see visually when chords change.  Optional to turn on /off of course.

Bump. 
 
Still my #1 personal request.

How about a tooltip popup that merely shows the note pitch based on the cursor position when you're ready to click?  Every control has these (switchable in preferences) and they've never really bothered me. 

Just did a bit of research and found that the tooltip shows up once there's a note placed.  So I guess you might do well to put a temporary note in place to read the tooltip which includes pitch, time, velocity, and duration.  
 
I'd still rather see the simple note location before I started entering notes, though.   A simple "Bb 4" that would help to locate the click point.  It would really help, especially when the PRV is zoomed out.

That's not it. It has to do with being able to look at a clip in the piano roll and see all the notes and what they are.