I hope it is similar to the Sorc ultimate "overload". Put spellcrafting in the "World" section and give it it's own passives and a few abilities to use. Then the "crafting" part of spell crafting could be different effects you can enchant your abilities with. These effects could be crafted by an enchanter.
I'm pretty sure Spellcrafting will be similar to Enchanting (also probably crafted with runes with the same uncovered properties such as fire, frost, shock, add, subtract, etc.) where you literally craft your own spell. Example: Fire + Add + Damage = Fireball with DoT.
For those worried about balance, it's honestly a piece of cake to balance this system. Just as with woodworking when making staves, you decide the damage based on your LEVEL and the materials you own. So they could give you like the max possible damage output and you scale down from there based on materials and the magicka it would use. Obviously the more damage the more magicka it takes out of you, the less you can cast it in a fight. So depending on your playstyle, you would choose if you'd rather have an ability you can use once, or multiple abilities you can use consecutively. They're just adding variety and choice. Personally I find the fact that no 2 players will have the same abilities to be outstanding and never-been-done before in an MMO.
I'm hoping they also give us the choice between which animations to use for each spell. As for particle effects, pretty sure they're based on the school of magic used. Fire magic will use fire particles, conjuration spells will use the purple particles in Daedric Summoning, healing spells will use the golden swirls etc.
Seems like a pretty basic, solid system to me. All it does is give you more freedom in playstyle and more variety between players. Balancing it is just a matter of making crafting materials rare and including a damage cap for spells in correlation to magicka and whether single-target/AOE.
Pretty sure it won't be a scroll with one-time cast as that would be ridiculous and not worth the trouble or materials used to craft it. Also would make potions redundant and pointless since scrolls can be self-cast as well. I'd like to think Zenimax are a little more creative than that.
Ohhh.... Yeeeeah. Since I get most of my fun from exploring and finding, I don't give a . about the Spellcrafting but finding the tablets? Heaps of Fun LOL
Oooh look, lot's of Butterflies! Wait! Butterflies? Get out of here Sheo, stop bugging me!
Having issues with Provisioning Writs? A list of problem Writs and people willing to help in game can be found in this Thread