Wave offers a text editor that's embeddable and allows multiple concurrent edits (which is what the OP requested). Having used both Etherpad and Wave, I don't really see how they're that different. Wave has more features, that's all. If you don't want to use the other features of Wave, well, just don't use them.

Well, I am the op, so let me elaborate.

By default, Wave creates new "boxes" for everything, or lets you reply to other boxes. These boxes cannot be rearranged, only deleted, or have the contents changed.

I don't give a crap about these boxes, I just want to edit a single document like EtherPad. To achieve this in Wave, have to arbitrarily agree on which box you want to make the "main" box. You then need to click the little tab on this box and choose "edit box" every single time you want to make a change to it.

You also can't track who has made what change in the same box. Also, your cursor turns into a long string (your name) that shifts everything around in an annoying manner.

It is sort of a cross between EtherPad, a chat client, and a wiki. I just want a text editor.

For reference: here is what an embedded Wave looks like: http://smarterware.org/my-favorite-google-wave-bots

Thank you, you just described what's bugged me about wave for a long time, I never really could put it into words why I liked EtherPad more, I just knew that I did.