EDIT: GOING TO CREATE INDIVIDUAL THREADS FOR EACH OF THESE THAT I HAVEN'T PERSONALLY SEEN REQUESTED.
 
QUICK DUPLICATING
Quick duplicate keyboard shortcuts for both linked and unlinked duplicates.
 
CLIPS --> BARS
An option to have recorded midi clips extend the full bar. For example, if you're recording a 4 bar section and your last note is on the 3rd beat of the 3rd bar you're left with a clip that doesn't extend 4 bars, but instead ends on the 3rd beat of the 3rd bar. You're left having to manually extend any recorded midi clips to keep things tidy throughout your arrangement.
 
QUICK QUANTIZING
Quick keyboard shortcuts for quantizing both note start and end individually.
 
TAP TEMPO
Tap to Tempo Control Bar button, or preferably a keyboard shortcut combination that allows us to tap our song tempo from our keyboard on the fly. (Hold Alt and press T to tap Tempo)
 
SAMPLER
A Sampler along the lines of FL's Sampler Channel or Studio One's SampleOne. It would also be nice to have the option to open Browser items in the Sampler by right-clicking and selecting "Open in Sampler" (à la Studio One).
 
CLIP COLORS
Return of more clip color options. Past versions of Sonar seem to have had more clip color options. One preffered option would be to have Background Color follow Track Color, with a lighter variation of the selected color for the background of the clip and the waveform following the exact color chosen.
 
ENHANCED EDITING - NOW TIME
Currently the 7 key is unused when using enhanced editing with a keyboard. It would be very helpful if the 7 key could position the Now Time at the Edit Cursor.

I could go for all your quick key shortcut commands.  But I've always have been underwelhmed by Cakewalk's instruments.  They never seem to be fully developed.