Wow comrades, that means, I have to choose between dual and 2H. But one question, do any of the attacks of these preferences needs magika? Since I have already invested six levels to it and don't wanna waste. If really no need, then I will stop investing there.
Then I will have no chance to use my newly constructed conjure storm atronach, right?
The following is just my opinion and I can only speak from my personal experience and research.
I would not invest anything in magika at all even if I wish to use a lot of magic, due to that via item crafting, you can create items that reduce the cost of magkica in %, eventually beyond 100%. That means you would not need any magicka to cast spells on a specific schools you have crafted your items for.
I also do not invest anything in stamina either, even without eating any Vegetable Soup.
If you wish to understand the game more before you make your decisions, I recommend you to have a look at pm00's video over on You Tube:
http://www.youtube.com/user/pms00
He is also a member of this forum and he tests a lot of things in the game.
It's your choice on how you use this information, or complete ignore them if they contrasts with you play style.
Good luck.