Coming up next…
Right now, I am reimplementing the client. I already did most of the theoretical design and I’m now in the middle of translating that into JavaScript code.
The next release will (already) feature basic Blips. You will be able to concurrently write text, add Gadgets and post replies. No formatting, images and inline Blips (i.e. Blips which you can insert in the middle of some text).
I won’t promise anything (as always), but I think I can do this within the next two weeks.

Are you interested in putting out the gadgets/widgets part as an external service?
I was wondering as we already have a working widget/gadget server – Wookie – that supports the Wave gadget API (example site here: http://getwookie.org/moodle/course/view.php?id=6) that could work well with an independent Wave server/client.
The web API for Wookie is pretty simple – the server publishes a list of installed widgets, you can get an instance of a widget, and add and remove participants for instances. Wookie handles all the state and event management.
Let me know if this is interesting…it could make the core task of building the Wave client/server more manageable!