That's right, I've implemented potions to the Master Sword Mod! For information on them, check out the 'What is this mod?' section at the top. If you find any new bugs or want to tell me an idea for my mod, feel free to comment on this post or say so in the Minecraft Forum!
I'm having a lot of trouble with the textures with 1.6.1. If you're a Minecraft Modder and willing to contribute to this mod and has the textures working with 1.6.1, help me out please :P