Is "glass cannon" a generally recognized phrase?

"Glass cannon" is a popular term in gaming (especially online-gaming), where it refers to a character class that has remarkable offensive power, but has low defense. Urban Dictionary also defines this as:

Refers to a person, weapon, or vehicle which has a high output, but a low defense, life, durability, etc. ^link

However, I failed to find any references other than the above one. "Glass cannon" actually sounds pretty intuitive, so one can guess the meaning even when hearing it for the first time.

Is this phrase generally recognized outside of the gaming world (i.e., could I use it in a general conversation and be understood), and if it is, what is its etymology?

I'm not a gamer, and I've never heard the term before now.

As to whether or not I could deduce its meaning, that depends entirely on context.

A similar phrase that first springs to mind is loose cannon, which etymologically has little to do with a cannon's firepower, but more to do with the dangers of a unsecured cannon rolling around on the deck of a ship.

Idioms using the word glass can refer to fragility (as in glass cannon), but the word often connotes transparency as well. A glass ceiling is something that you know is there, even if you can't "see" it. However, glass ceilings aren't exactly known for being easy to break. In software, glass box testing (more commonly called white box testing) means that the testers can "see" the inner workings of the code when designing their test plans.

In short, I wouldn't count on people being able to figure out the meaning of the expression merely by examining the two words put together. That said, the phrase might still be decipherable in some contexts, depending on what other clues are present.

Outside of the gaming world it's not really used. However, it's a nice expression and I think it would be understood.

That reminds me of Diablo 3, where character class like, Demon Hunter / Wizard usually falls into this category. I don't really hear this word anywhere else except in the gaming world.

Another similar example would be Meat Shield, which is also very often used, which is opposite to the meaning of Glass Cannon.

In my experience Glass Cannon is also a term used in Collectable Card Games (Magic the Gathering) where a combination deck will be totally unable to recover in cases where the combination is countered/disrupted.

In this sense where the combination succeeds it results in a game win and when it fails it is a certain loss as there is no way to recover.