A clean, modern RTE has been needed for a long time - would this be the one? Unless of course RTEs are really not needed anymore, which may well be the case.
Anyway, it would be nice to have at least an overview of the architecture of this editor. I'm a bit hesitant to use an editor as a "black box" plugin, because it means that a minor customization may take days of work (or even tossing away the whole editor) in case the architecture is bad.
* basic HTML markup (headlines, paragraphs, lists...)
* HTML tables
* images (data:// URIs are good for handling pasted images) and an image/file browser, complete with some image processing that rejects or shrinks down giant images without ruining the image quality, because people will upload giant JPEGs straight from their phone if you let them (naturally, file uploads come with their own cans of worms like server security, disk space, file permissions, growing backups, etc.)
* black magic to cope with Word's markup
Don't forget to make sure that the end result looks consistent with the rest of the site without the users having to manually set the font family/size on all their text... and that the editors can't turn off the RTE and post raw HTML with malicious intent... and a million other things.