So I've decided there are two ways to play Terraria: The fun way and every other way.
The fun way involves no cheating and absolutely no cross-world twinking.
Pretty much ever other way is the other way.
Because what really defines fun in this game is the challenge. The exploration is fun, but it's only fun because of what you seek.
People that I started playing Terraria with are liking the game more than people who have come in after release and just had grappling hooks, armor, weapons and full developed worlds thrown at them. They're still having fun. But not quite as much.
So yeah. Once me and my friends max out our current characters, the only way I'll be playing Terraria is in PvP, with fresh characters or to check on updates. Going to a new world with a maxed out character to be maxed out just isn't the same level of fun as slowly clawing your way up the item scale, and dealing with all the world's challenges without the best stuff in the game.
It kind of makes me pine for a Terraria that is more rogue-like. Maybe I'll start playing the iron man games. I don't say all this out of whininess or bitterness about something; I just don't want the awesome to end, and I can feel it steadily creeping up in our game, as I stockpile our 15th hook thinking "who is ever going to use this? And who would I honestly want to deprive of the fun of going down to get their own hook?"
Even without a leveling system, there is just something so amazingly well done about progression. Maybe it's the fact you start with absolutely nothing and crap gear, that every find is like your birthday.
I'm hoping that someone mods in Terraria that is built for 40 to 50 hours of play time instead of the ~20 it is now. The game is still epically long for its scope, but I wouldn't mind stretching out a single character play through over a couple months of solid gaming.