I agree that new terrain to explore is the main attraction. I believe having a map 2.5 times the size with 1.1 times the content isn't very useful though. That's why I won't put out a full release.
So much work was done behind the scenes and with new mechanics. I doubt anyone but a programmer would appreciate the work that went into these mechanics. There's over 2200 lines of code server side in just the core of the tile hardness mechanic alone. Not to mention the integration snippets here and there, or the client side bit. The liquids code was quite the challenge. A lot of things were rewritten to give that mechanic so it can scale with liquids and more randomness on the generated block placement. Then we have the Starmap. There are 3 components of the Starmap that had to be created: client side, server side, and master server side. Then the call for vehicles comes in. Originally, I didn't know how in the world I was going to make that happen. When the mount system came out for Terraria I decided to use that. Now, I've decided to go in a different direction with vehicles. I'm moving all of my code out of the mounts and creating whole new entities for them.
So, where does this leave us? Well, that a tough question. I'd be willing to put something legit out if I finish the crypts, the molog den, and all of the early items content up to hard mode. On that note, how close are we to that goal? If I had my way the crypts would be done inside a week and the molog den maybe another week. The early industrial item content isn't really hard to implement unless those items relate to some other mechanic that's labor intensive to create.
I'll end the rambles there and leave you guys with some pictures.
This is the Bonepile Spawner that will be in the crypts. It's main function is to spawn enemies thereby making the crypt zone fun and challenging. It will also drop an item used in the crypt for something
1. Inactive - On screen player not in spawner's zone.
2. Active/Idle - Player in spawner's zone.
3. Agressive Spawning - player in spawner's zone and in spawner's line of sight.
4. Enraged Max Spawning - player in spawner's zone, in spawner's line of sight, and within aggro range. OR Spawner has taken damage and is within enraged count down.