So with that in mind, let us see what benefits we might get from the stand-alone path of Magic.
Spells
It is very hard to find a good game, where they include an awesome magic system. The biotic system in Mass Effect is neat (although it still has more potential,) but it isn't really magic, now is it? Even Bethesda, in my opinion, have always had trouble with this, but it looks like they've definitely remedied that in Skyrim.
Apart from making a very wide array of spells, Bethesda has made a unique animation for each and every spell and mana regenrate a lot faster, so you'll be able to make good use them even before you raise your magicka to brutal heights.
Furthermore, the spells can solve all of your problems and in a lot of different ways, enabling you to pick the technique that speaks most to your nature. See a group of bandits in the distance? Well, you could cast Frenzy and watch them take care of each other - Or you could set a (rune)trap and then taunt them to trigger it with a well placed fireball to the head. Glorious!
In the beginning , you might feel that powerful as a mage, as Todd Howard said, but eventually you will grow as a magician and come to feel very, very powerful! You've surely seen the mind-blowingly cool spells, such as the AoE fire spell, which looks nothing short of brutal.
One of the major perks of the mage's spells is that you don't have to carry around heavy equipment, due to the "bound" magic, which temporarily calls forth either armor or weapons for your convenience. Unlike Oblivion, it seems that we won't be grabbing Daedra equipment, as the picture of a dude with a bound bow suggests. Instead it'll be kind of "Astral" goodies, but none the less, just as lethal. The only thing missing when you use a bound spell is the sound of three light nodes and a woman saying "Because your worth it." - Unfortunately Bethesda didn't take any of my suggestions.
As always you can pay other magicians to learn these spells, or you can learn them through the various spell books throughout Skyrim.
Crafting
A mage's primary crafting skill is Enchanting, allowing you to break down the enchanted weapons you find in order to learn the enchantments they had, and permanently be able to apply that enchantment to everything else! Glorious! Also, when you enchant something it glows with the color that applies to the used enchantment - So if it is fire, then it'll glow red and if it is ice, then it'll glow blue.
Guild
The guild that applies to the mage, is the College of Winterhold! Located in.... Winterhold! Good guess, grasshopper!
The college of Winterhold is solely a mage's guild (You can join no matter what, so don't worry,) but the possibility that you can go and grab the title of headmaster, like you could with all of the guilds in Oblivion, has only been hinted at, but not completely confirmed. Personally, it sounds to me as if you can.