Don't think anyone asked this, yet...
What kind of relation will there be between strange moods dwarves have currently and the secrets/curses spirit-interaction stuff that's coming in this release? Will the two systems become one eventually?
Artifacts were intended to be the starting point of the magic and spheres system, but the new secrets and interactions have beat them out the gate it seems. There's nothing specific about magical artifacts on the new dev pages though, so I don't think there's any timeline.
Well, if the gods a dwarf worships can influence the artifact made by a strange mood, the god's spheres could influence what artifact is made, without having to bring magic into it. The god's spheres could decide what type of artifact is made, rather than the dwarfs skills (WAR sphere makes armour or weapon, etc), and also the materials used (TREE makes wood be used, WEALTH increases the chance of decoration with gems, etc).
Or, perhaps, the gods worshipped by a dwarf influence the sphere's an artifact acquires. So a dwarf that worships a god of death, consolation, fortresses and wealth might create an artifact with any of those spheres, though it might acquire more the same way gods do. What effect the spheres of an artifact had is a whole other question. For instance, an anvil with the fire sphere might cause a workshop built with it to never need fuel. A throne with the war sphere might cause whoever sits in it to gain 1 point in a fighting skill for every frame they sit. A hammer with the death sphere might sometimes raise the bodies of its kills under its wielder's control.
Really, I don't think we have anywhere near enough information to begin speculating on what the effects of artifacts will be. For now, we are getting an awesome set of curses, undead, necromancer, and were-chihuahuas. Sufficient is the day for the !!FUN!! thereof.