There's no final version. Nothing is static, everything is changing. With every new iteration, small changes make you realize the creature is alive. You're never bored: sometimes they're doing small tests and you get the chance to see things before they're launched, in other cases the evolution takes you by surprise. As with most beta software, there's no guarantee that things will go well, but this new perpetual beta removes most of the risks because the changes are much smaller.
When a product is still in beta, you never know what's going to happen next. It may change its direction, it might morph into something else. It's an unfinished product, like we all are, always open to new horizons.
It's like writing a book, publishing it and then realizing that you should have written something else. But you can't change too much until the second edition. In the web apps world, the second edition can be launched much faster and it doesn't require buying a new copy.
With all its mistakes, the beta application is honest and admits is not yet perfect. It's still testing, exploring, challenging the possibilities.