One new idea from 4th edition D&D that I think is really great is the idea of making noncombat magic into long rituals that cost money.
In a fantasy game based around a world of magic, you want magic to be an amazing force that can do practically anything. But fantasy is also supposed to have a flavor of the medieval, and feature non-magical characters using their skills and abilities in a nom-magical world. This runs into problems when you also want to support wizards with stupendous powers. It isn’t very exciting being the world’s best cat burglar when your buddy the wizard can easily duplicate all of your abilities with spells to bypass traps, open locks, fly up high walls, or just teleport directly into the enemy fortress. Yet all of these are abilities that a wizard character might reasonably ask to have.
One way to cut down on the overuse of magic is to make it a precious resource. This fits a lot of fantasy material very well. When using typical magic systems, players can trivially use magic over and over again, as if they were using superpowers. In the actual fantasy genre, magic is often used sparingly, which is more appropriate and better for game balance. But figuring out how exactly to limit the use of magic is tricky.
The great idea of 4th edition is to transform these noncombat magic powers into a ritual, which basically acts as a form of consumable magic item, rather than an inherent character power. It costs gold to buy a given noncombat spell, and gold every time you want to use it. Gold becomes the precious resource that is being spent to use the magic. So you can make many amazing powers available, and players will not abuse them over and over again. The natural miserliness of players with long-term resources can make them covetous of their magic, just like in the source material.
Also, rituals now take a long time to perform. This helps differentiate rituals from normal skills. In many of the situations you would want to use skills that might be superceded by magic, using a ritual just won’t be possible. This helps prevent skilled characters from being totally overshadowed by magic.