Honestly, given what's gone into this one and what's apparently under the hood (from the sound of things, most of the major pieces to get to Beta are going in, other than Outposts / some sort of strategic-level metagame, and, of course, content) I can't say that I'm either worried about the length or concerned about it, frankly. This part was going to take a while. At least now it's relatively smooth sailing to the end, other than the last wrinkles UI-wise.
If there's anything I've learned from watching this project get done, it's that the low-level code support needed to get the high-level content done is a prime strategic task; stuff like the backend data structures, file handling, and UI framework, etc. eat a surprisingly large amount of time.