Jeb, Dinnerbone, Grum, and EvilSeph have been discussing the upcoming Mod API in detail! This is only a small look at the massive amount of information provided about the Mod API, so let's dive right in!
Will mods have the ability to modify text?
Mods can have config files that, when initialized, will be able to dynamically print text in a variety of ways.
Will mods like Optifine (which modify the engine directly) be supported?
The API will eliminate the need to write to the engine directly, allowing modifications that affect the game (as any mod will), without altering the game code itself. Among other things, this will greatly simplify mod installation.
Can vanilla block behavior be modified?
Will there be official community resources (tutorials, forums, etc) for modders?
How will mods be distributed by modders, and downloaded by players?
Players will be able to download mods from the game client itself.
Will the API be able to add new mobs to the game through mods?
Yes. Additionally, it will be possible to modify animated blocks (water, lava) as well as custom animated blocks.
Will the API be like Bukkit (an outside resource)?
No, the API will be integrated into the vanilla game, hopefully bypassing the need for exernal APIs.
Will client-only mods be supported by the API?
Not at this time, but as the biggest client-only modifications are already covered (texture packs, splash screen text etc), it didn't seem necessary.
Will the API remove the issue of mods being rendered inoperable when the game updates?
It is a target we want to hit for certain, but it won't really have that capability at launch, we don't believe.
Will mods need to be re-written from the ground up with the API's release?
While mods will need to be changed to accommodate the API, total overhauls shouldn't be necessary. Even if a mod requires an overhaul for the API, it would only be a one-time occurrance.
Will there be any sort of content filter?
By and large, the community will police its own mods as it does now, but we are working to put a system in place to prevent malicious mods from being distributed.
What can be modified in the game using the API?
Can the physics be modded?
Will the API be on the XBOX or Pocket Edition?
Not by us, but you can ask the developers of each game, respectively.
Will mods like Optifine be added to vanilla?
Something even better. Overall, the game engine is being simplified, taking most of the load off of the client, and having the server doing the heavy work, greatly improving SMP.
Smoothstone stairs are not planned.
No new mobs are planned.
Check back for more updates soon, there is a LOT going on today!