Well, that’s what Textflow calls their not-yet-in-beta collaborative editing system. It certainly looks attractive, it even looks like it might be nice to use. I have only had a quick look, but it claims to offer more than just multi-user document editing; instead of requiring editors to check-in/check-out portions of a document (hence locking their edits), Textflow chunks the document down into a database of edits and revision pieces of arbitrary size and maintains all the pieces of a document simultaneously over many editors. Its killer feature might be the ability to import several versions of a Word file and build a revision history with a ‘final state’ copy ready to commit or roll-back edits.
Faces stiff competition from Google Docs and ThinkFree (among others), but they look to be raising the bar.