It was launched as V3, but Jeff made such substantial and drastic changes/updates to it during subsequent development that he abandoned the V3 concept and moved everybody to V4. Those who have been given a personal preview of V4 were unanimous that it is indeed drastically better. Some preview pics were sent to us a while back showing the battery as a separate disconnected unit rather than integrated, and that more mounting options were possible, such as on a seatpost.
It's been a while now since we heard anything, last in April. Jeff expected production to start in June. Another month would easily be possible due to supplier delays so hopefully they're just in production now. If so, I expect another update shortly.
I wish he had been better about communicating that. I was on the mailing list but not notified and just gave up on v4. I am backing the Urbanext all-in-one-wheel and I have to say their communication has been very impressive. Two days on emailed questions and no more than 5 days between responses to comments. First backers should be getting their wheels from UPS in a week. But I really wanted a shareroller; I just thought he had shut it down. :-(