I don't think they'll be making it. I can't count the projects anymore that tried to be a "better facebook" or "better whatsapp". The harsh truth ist: people simply don't care. The number of people caring enough about their privacy to move to another social network just because of that (that seems to be ellos single selling point) is very very small. It will only be a couple of hipsters showing off how cool and different they are. In a couple of weeks, nobody will talk about ello anymore.
Its a bit sad but thats how it is. Just look at all the other approaches that have failed already. Even app.net that had a lot of media coverage failed in the end because people just don't care. Even the oh-my-god-we-are-so-awesome-and-invite-only trick won't do it for them if they don't satisfy a very strong need for the users - and they don't; because there is none.