I think his kit will be somewhat the same as it is now. Aura's galore. There may be a few tweaks, a new ability or two, but I don't think gameplay wise, he is a Sion level project. Visually is where I think the designers are having the most work. They want to visually remaster him and that involves updating all of his in game animations, his in game model, his VO, his ability icons, all skins, and possibly his splasharts.
They have stated that they want to fit his theme as a noble and kind protector, so he will probably still have his heal or a shield to fit with that, and I think his W is what kind of defines Taric. This armor stacking monster against high AD comps. They might think about giving Taric more tools to stick to his targets, but they might do something that will surprise me and change up the way I play Taric.