In no particular order or estimated delivery time:
duck audio
make it easy to add 0.5 or 1 second transition on timeline
audio noise reduction
open HEIC images (already works on macOS, work-in-progress in FFmpeg)
read Kyno XML for name, comments, tags
SMPTE 2084 PQ HDR
HDR preview (in-app, not external)
additional editing modes/operations (slip, slide)
fullscreen playback on current/single screen with on-screen controls
project media management (automatically copy or move to project folder, automatically convert)
archive project
raw video processing - e.g. CinemaDNG
multi-camera editing features
convert generator UIs to QML
keyframes for generators
partik0l generator
circle VUI control for Vignette and Crop: Circle
generic filter UI (MLT service name and table of parameters)
OpenFX and VST2 plugins using generic filter UI
multi-track transition
generic transition (MLT service name and table of parameters)
CMX EDL import
Kdenlive XML export
OpenTimelineIO import/export
add presets to Filters search
option to view timeline waveform per channel
add transitions in Playlist
add speed param to Export > Codec
option to reduce number of encode threads for Convert, Reverse, and Proxy jobs
improve the appearance of video-with-alpha clips by showing with checkered background in source player
background removal
universal search
add a base VUI that adds indicators for in and out points and a toolbar to invoke filters:
Text, Size/Position/Rotate, Crop, Color, Chroma Key, White Balance
improved UI for nested projects (MLT XML clips)
multi-select support for Properties
multi-select support for Filters
option to include intermediate thumbnails in timeline
ability to set the poster frame for a clip
add Recent and Most Used tabs to Filters chooser
more columns and sorting in Playlist
clip markers or flags
turn off all effects switch
aspect ratio lock for VUI rectangle control - e.g. when used with Crop: Rectangle
motion blur for motion-animated things like Text and Size/Position/Rotate