http://elderscrolls.wikia.com/wiki/Spellmaking

I think that spellmaking would add alot of diversity to gameplay at both pvp and pve. Combining various effects into one spell or making a spell that does damage over time instead of when it hits. There would be a lot of possibilities and i think that not knowing what kind of spells you would encounter from an enemy mage would make the game a lot more interesting.

Just don't give us Skyrim-like gimped mages with 10 offensive spells which $ucked beyond belief. I am sure that it can be balanced out properly and to everyone's satisfaction.

Would be interesting, I finally realized I didn't have spell making after playing Skyrim for a while. LMAO But can only speculate functions and use about crafting.

I could see this viable as with Alchemy, Smithing, Cooking, etc.

It's possible... but that sort of thing can be very tricky in an MMO. You can't make player made spells overpowered in any way, and would need to keep them in line with already-existing ones. It can in no way place you in an advantage over other players. So, where does that leave spellmaking? Pretty watered down from what you were used to in Oblivion, to be sure...