I just found a possible visual preview of macOS 10.14.x here:
https://www.macrumors.com/2018/06/02/ma ... eo-leaked/
I like the look of the new transparent menu bar (edit: not transparent, just dark ):
(edit (again): ...aaaand macOS dark mode is already available in macOS 10.13.x so the only new things here are dark mode in Xcode (not particularly relevant to the Pixelmator community) and a dark recycle bin. So, ladies and gentlemen, I bring you a forum post to show you a really pixellated image of a dark recycling bin. Enjoy. )