I haven't seen anything mentioned about this, so I'll ask these 2 questions here:
1. If an update to tModloader becomes available, will we be able to halt the update(s) to it and still play Terraria untouched until we wish to update -- ensuring our worlds/mods won't constantly break every time tModloader updates?
2. Will it be easy to halt each individual mod update until the user wants them to be installed?
Both tModloader and mods themselves update frequently. Immediately updating these also tends to crash Terraria when loading a pre-existing world, completely break worlds, if not at least cause multiple minor problems. So these 2 questions are rather important -- as long as it's easy to continue playing Terraria unchanged until the user is ready to install updates, all it well. It sounds like all downloads/updates will occur within Terraria's in-game mod menu, rather than on Steam out-of-game -- that much is very good news.
One thing that worried me about mod support being tied to Steam, is the fact that Steam (in most recent years) makes it near-impossible to disable various game updates and still play said games untouched. The best thing with
not having any mod support is that when a mod updates, there was no worry of a mod updating without your knowing or consent, then completely breaking a current world you're playing on. If mods were integrated into Steam itself in any way as separate downloads outside of Terraria, this could go
very badly... between tmod updates and updates to mods themselves.
Modding with other games on Steam can often times be a nightmare whenever mods update or the games they're played on update, because you're frequently forced to break your modded games on Steam, then wait sometimes weeks or months for those mods you like to catch-up with the game's update, or if possible, roll-back to an older game version just to make a beloved mod playable. I love modding this game, but part of the reason I love modding Terraria is because it's been relatively without any headaches in my experience -- here's to hoping it stays that way. If not, I'd thoroughly urge to implement a way to allow for halting updates of any kind (while still being able to play the game in the meantime) until the user is ready.
This one big concern aside, I'm
extremely happy to know this modding community is 'officially' getting the love it deserves. While overdue, it was unexpected and really great to see happen!