Member Rara Avis
In theory, there are only a finite number of possible (let alone good) moves in the game of chess. In practice, of course, no one has yet to play them all...
I think the same is likely true of metrical structures. One of my greatest delights in poetry is discovering a new poem not only with an exciting structure, but with one that becomes an integral part of the content. Okay, it doesn't happen often. But, boy, when it does...
In other words, I don't think meter necessarily relegates the writer to the past. I think there is a "future" as well, albeit one with a devious path. Brad, I think your own "I want to be adult" is perhaps a good example, where the meter and structure are both a step away from the typical and very much a part of your Hemingwayesque story. Does meter limit us? Yes, probably. Does it limit us to what has already been done? Not in the least.
However (I straddle fences very easily ), I will also readily admit that free verse does grant a freedom that is very appealing. Personally, I don't think free verse is any less structured than metrical verse - but it is less obviously structured. In meter, a poet's structure has to be seen, has to be almost predictable in order to be successful. The structure of free verse, I think, is more subliminal. But I still think it is very much there, and I think the reader both "senses" the structure and is jarred when the poet deviates too far from it.
Coincidentally, just last week I was reading my way through Open Poetry and realized we have a disheartening lack of free verse posted. And I know we have some really incredible poets who write both styles and some who write only free verse. I think it's important, to all poets, to have a balanced diet...