1 Varispeed 
2 More and better notation (staff View)
3 A "P5" project theme

I was a cubase user for 15 years, since using sonar from X1 onwards I have never looked back. The only thing I would love to see is a staff view that matches the professionalism of the rest of this amazing software. Right now it's awful, but I live in hope.

1) Improvements to the matrix view. At least to directly record into a cell.
 
2) ACT II
 
3) Better browser with tagging

1. Expression Maps - Essential for orchestral scores
2. Chord Tracks - Handy for us that keys isn't our first instrument
3. Redesign of audiosnap - This is a long way off.  Ideally would have instant realtie warping like Ableton and phase cherent multi track editing

MarioD
3-no more updates that would make a perfectly running and rock solid function either unstable and/or unusable

+10

wizard71
I was a cubase user for 15 years, since using sonar from X1 onwards I have never looked back. The only thing I would love to see is a staff view that matches the professionalism of the rest of this amazing software. Right now it's awful, but I live in hope.

Could you outline exactly what the current SONAR staff view is lacking in comparison to Cubase? Very curious about this. 
-DG

Score Editor

The Score Editor is a professional notation environment with full support for just about all symbol, display and editing options that this entails, including support for lyrics and remarks as well as drum notes, guitar tablature and lead sheets. Simply select the tools needed to create fully professional score layouts for others including soloists, orchestras and choirs. The Score Editor includes more than 100 professional notation symbols and supports the import and export of Music XML files.
 

Did the Steinberg kids program their editor in house or did they farm it out/steal talent from companies like Sibelus?
 
I still think the staff view stuff should be contracted out to a third party so as not to distract the Bakers from their current work. Since a huge amount of your users are guitar players (like me) and GuitarPro does notation very well as far as I've seen I'd say tapping their resource/talent pool would be the best bet. Tab AND notation would be freaking brilliant and likely set the notation element of Sonar aside from the rest of the pack.
 
Essentially I would like to see Guitar Pro integrated into Sonar's MIDI editor somehow.
 
Just as long as we have a Baker poking about. ;-)

Oh boy, take cover.

I second (or maybe third?) the cakewalk/Izotope collaboration.  My only other request would be to expand upon the options available in the step sequencer.  Especially as it relates to the groove and/or style of any given patterns playback.  Its entirely possible that this is already a function that I just havnt found yet.  But in my opinion, the "swing" dial is a bit too subtle.
 
All in all, SONAR is one of the best investments Ive ever made, x 4!