I'm actually hoping that 8.5 / 9 will have some major updates to existing features / GUI that have been around for years and desperately need an update.
1) "Always on top" for every single window...including the Pool window, mixer (when it's not fullscreened), connections windows, etc.
2) Complete revision of the color palette menu. It is currently a click fest, having to use the pull down menu every single time you increase / decrease an intensity / saturation parameter. Strangely, it used to be better 2 or 3 versions ago. All of the color selection options should be in one single window interface. Perhaps also a couple large color preset collections to choose from.
3) Also about color - perhaps a few complete GUI color presets for the whole software...as well as (perhaps) more separation options for various windows...like the track list background having a separate color option from the inspector background. I do like the very versatile color options that have been improved in the last few versions, but it would be nice if Steinberg created some strong and well thought out color scheme presets for people to choose from as well.
4) Better exchange of information between various versions of Cubase / Nuendo - for instance key command and preferences transfers. Trying to figure out how to get Cubase 7.5 key commands into 8.0 has been interesting, and far too difficult.
5) A rethinking of the grid / quantize / nudge palette function in the tool bar. This has been around for years and years, and using other software, I believe it could be handled far, far better, and also less of a click fest. Currently there are 4 different toolbar sections for snaptype / gridtype and quantize presets - 2 of which are pull down menus. It would be nice to have a dockable interface without pull downs, and all the grid / snap types in one box...all displayed at once...much like some delay / modulation plugins. Nudge palette is not necessary to include in such a window, but the current setup is old and tired.
Example of what the pull downs look like now:
http://i.imgur.com/qKRUAPk.jpg
Example of the same type feature in LFO Tool (a bit ugly UI, but whatever) taking up 1/4 the space, including triplet, dotted, sync and no pull downs:
http://i.imgur.com/e0gw1RR.jpg
The triplet / dotted, etc. options could be hyper simplified by just having a triplet / dotted button instead of listing all 15+ options in the pulldown. Inefficient design like this is all over Cubase / Nuendo.
6) Right click tool bar / menu commands when "Pop-up Toolbox on Right Click" is disabled. This is also a very old feature that just looks messy. Would be nice in the preferences if we could customize / remove various features from the right click command, and specify what is actually listed...instead of every single thing being listed. Example of what it currently looks like when right clicking on an event:
http://i.imgur.com/wKtuXsD.jpg
That is a mess.
7) VST Connections window. Changes and routing selections made here should have the option to be permanent and global. How this is not the case already boggles my mind. Selections made here should also be tranferable to other cubase / nuendo versions...and as mentioned earlier, the same goes for preferences and key commands.
8) ALL transport bar features available in the top tool bar - basically having the option of docking the entire transport . Currently only some options are available, which is odd.
9) Combine the pool and the media bay...or at least offer the same dockable option for the pool. This is a no brainer I think. The pool window should be one of the more important dockable windows, along with the instruments / racks / media bay. Although it would be nice to combine the same explorer / audition options from the media bay in the pool, I think it would just be nice not to have a floating pool window that is incredibly frustrating to use - especially since "always on top" isn't even an option. I have worn out the "p" button on my keyboard from all the CTRL-P use over the years. Seeing how easy the mediabay / racks are to access now that they are docked, it makes sense to do the same to the pool window.
10) The ability to a) trim a clip down in the pool prior to drag / dropping it into the project - basically having a waveform display of the clip, being able to set in / out markers, and then dragging only that selected section into the timeline. Having these markers locked to tempo (like the mediabay audition) - so if you're in musical mode with a drum loop and can easily snap in our points, and then import. :D This would also work great for audio editors - like say you have a 20 minute audio recording of car door slams, you could just audition via a waveform display in the pool / mediabay, find the door slam you like, highlight the section (in / out point) and drag into timeline. I have no idea why this hasn't at least been implemented in the media bay. Currently you have to import the whole clip into the project and edit it there - wasting harddrive space and time.
11) This applies to the others...but better handling of projects opening, browsing. We're still back in the 1990s pull down "file open" pull down "recent project" etc. school of thought. The Steinberg Hub is a mess and virtually unusable. Project browsing, opening, organizing should be available right from the project windows - with ability to select favorite projects, favorite project folders, project templates, etc. all from one window...preferably a dockable explorer window that doesn't require a bunch of clicking, shortcuts, etc. to get around.
12) Import session date...as benmarx pointed out. This also goes along with the sharing of information in Cubase / Nuendo and how it is currently very fragmented. Being able to import / export information (preferences, key commands, session data, even the fx presets system is very messy and inefficient) is all very lacking in both of these programs.
13) Goes with a couple others above - storable everything. Ability to store preferences, key commands, plugin setups, windows setups, connection settings, etc. as actual files that can be stored anywhere and backed up separately. Can't count the number of times I've lost plugin settings (especially after updates or crashes) only to have to go through them all again and set everything up again. NOTE: This just happened in Cubase 8 about 5 minutes ago. Went through Plugin Manager - made two different setups...one sorted by plugin manufacturer, one sorted by plugin type. Went beautifully. Then Cubase crashed and it lost everything I had done. Uggh.
I'm sure there are a bunch of others, but this was a quick list. All in all, I think Cubase suffers from some tired menu, color, navigation and global preset problems that could be quite easily solved. Reducing the amount of menu pull down, docking more features, combining fragmented features (eg: pool / media bay) allowing global and easily transferable presets / preferences / session data all across the software would all be very welcome.
I would definitely like to see changes like this over major new features added in the next version or two.