Does anyone know how to make a new liquid with King Lemming's new BlockFluid class? I've been messing around a little and I can only manage to do this by making my own BlockFluid class, and even then textures don't work... any ideas?

it's pretty simple. just use this as a guideline and register the fluid before the block if the fluid is binded to a block. most of the methods in the BlockDigitalSeaLiquid file just add custom things to it. you only need the constructor (and you only need the super() line of it).

	@EventHandler
    public void CodeLyokoLoad(FMLInitializationEvent evt)
    {
	ModFluids.init();
	ModItems.init();
	ModBlocks.init();

https://github.com/code-lyoko-modding/CodeLyokoMod/blob/master/matt/lyoko/fluids/ModFluids.java

https://github.com/code-lyoko-modding/CodeLyokoMod/blob/master/matt/lyoko/fluids/BlockDigitalSeaLiquid.java

Thanks! How would I then do custom textures? I get kind of confused around the arrays and I'm not sure which method actually registers it, considering I can't find a registerIcons function.

You register it with the setIcons method in the fluid it block. There's a post somewhere that explains the textures. Let me find it. Here it is http://www.minecraftforge.net/forum/index.php/topic,10319.0.html

Note: I don't think the system I described for setting the Fluid textures in that post is how it's intended to be done. I simply can't find any other solution, and the documentation for that area is quite poor. This new Fluid system is very convenient, but I don't think it's finished.

I just changed the color of water and used that. That's what the getIcon method and colorModifier method do.