Well, he has a set of goals he intends to achieve before it hits 1.0 and the version numbering currently is meant to reflect the % the brothers deem it complete. Considering they've managed to spend ten years doing the work I would say it seems possible it will, eventually, hit beta and even be 'finished'.
Well, it is currently at 0.43, and since we know that the last 10% of the project takes 90% of the time we can expect the 1.0 to release in approximately 232 years.