Well, yes and no. I've been experimenting with throwing in a few very mundane looking magical items here and there. For one thing, it makes players stop and consider what they're looking at when they find a simple iron ring or a plain pair of leather gloves. Of course, that's not a good enough reason. There needs to be some kind of in-game logic, there can't simply be a meta-game response (I like the thought that they might accidentally get rid of magical things, since I'm always afraid of the dreaded magic inflation).
So here are some little bits of reasoning as to why magical items might be plain looking:
- A WIZARD DID IT. You can never really tell with these guys. They might make something plain magical just to screw with you!
- There is as much power in hiding something as in displaying it. Sure, the overly ostentatious ring might be magical and thus might be a warning not to screw with this guy... alternately, it might just be an expensive ring. But the next time you pull a sword on a dude wearing a simple iron pendent, you'll be VERY surprised if it can throw fireballs.
- It is a relic of a once-living character OR it has sentimental value.
- It became magical not through enchantment, but through picking up attributes over time (ie, a sword that was used to slay ten thousand goblins, which now lusts for their blood).
- The personality of the item's maker.
- The culture of the item's maker proscribes it.
I think the most powerful argument here is the argument from secrecy. While it's true that 10th Age wizards wear bright flashy robes to announce their amazing powers, it is equally true that there are those who dress simply or even in peasant or merchant's clothing to fool the people who would hunt them or confront them.
Dwarves in particular are known for their aversion to displaying wealth to anyone outside of their own people. They are terrified that men will want to rob them if they wear precious metals, so they often dress in simple colors when outside the folkhall and wear no jewelry or only very basic jewelry. This makes a good argument that some dwarves might craft magical items to be equally unobtrusive.
So, in the end, more simple and humble-looking magical items are going to be appearing in the 10th Age games... though not TOO soon, because I don't want to overdo it on the magic.