I know what you mean... the smell of a new game book is rather intoxicating to us damnable geeks.
SW would definitely be easy to explain to 12-14 year olds. Character creation is also pretty quick, and because there's not a huge shopping list of skills, it doesn't overwhelm newbies. Storyteller pretty much was my system of choice, but it has been replaced by Savage Worlds. For me, the best thing about it is that it actually has an internal logic to how things work, and once you grasp it (not difficult, but definitely "between the lines"), you can do just about anything with it without resorting to a host of "house rules."
For a teaser on magic, keep reading...
SW Characters have access to things called Edges (basically similar to Feats in d20, but with some extras). There's a group of Edges called "Arcane Backgrounds." These include Magic, Miracles, Weird Science, Super Powers, and Psionics. Each has its own flavor, but generally give you a certain number of Power Points to use in purchasing Powers. Powers are spells, devices, whatever that generate an effect as listed in the book.
The Powers are typically kinda generic, and you add whatever trappings are appropriate for your game/character. For example, there's not several different spells which all basically do variants of the classic Magic Missile--you have "Bolt", which costs between 1 and 6 Power Points to cast, allowing you to fire anywhere between 1 and 3 bolts of varying power.
Magicians typically get three powers to choose from, and you can buy new ones whenever you level up. Some have requirements of certain Ranks (similar to Levels in d20) or other Powers or Skills. You can also buy extra Power Points when levelling up, too.
Weird Science dudes get a set number of Power Points as well, but they work a little differently. They're actually stored in a device that creates a particular effect. This lets them hand their gizmo over to someone else, who can then use it. Each time a Weird Scientist buys a new Power, he creates a new device with its own Power Points (meaning you could make two "death-ray pistols" if you wanted).
For real fun, you can add a Professional Edge or two to make your character really unique. A great thing to do is add the Gadgeteer edge to a Weird Scientist. This lets them make a one-shot device, once per game, that can duplicate any Power listed in the book. After it uses up its Power Points, it fizzles and doesn't work anymore.
Ok, I'll stop rambling now... lol
) I won the coupon in an adventure writing competition for D&D on E. N. World if I recall correctly.