The Sunday Times had an interesting article by David Orr on the subject of greatness in poetry, or rather, the apparent lack thereof in recent decades. It suggests that Elizabeth Bishop may have been the most recent Great One. Hmm.
As Orr notes, poetry is one genre whose whole reason for being would seem to be to swing for the fences. Sure, there's light verse, limericks, doggerel, etc. but who would care really if these vanished from the earth? What we crave from poetry, if we crave anything, is something that will blow us away, change everything if only for a moment. Yes, this is a highly Romantic conception. But where are the classicists who actually read the likes of John Dryden or Alexander Pope? Poetry is the Romantic genre.
What separates the Great from the Merely Very Good? No more perhaps than separates the Tall from the Of Above Average Height. The Great--in anything--is just a repository of cultural value, beyond a threshold established by social consensus. Of course, look around these days--who's around to assemble a consensus? After all, when I just reflected on the cultural valence of greatness a few moments ago, one of the first things that came to mind was "They're Grrreat!" courtesy of Frosted Flakes. The offspring of advertising and poetry are sterile.
At any rate, here's a poem that I found to be striking, if not Great (it's already publicly available at http://www.tnr.com/):
A sky out of Thomas Hardy: bleak, cloud-broken, swollen with
wind-shiver, grey-gold with touches of crucifixion and apocalypse,
everything a flight, a fugue, so the small voices of these slate juncos
make music a huddle of refugees might make--bedraggled, bent
under tattered loads, feeling the weather change, the air harden,
the taste of things grow harsh and crude on their forced march
towards haggard light, towards some poor haven, this endless trek
against weather, firest blossoming from the sky ceiling, the ferocious
thump of air waves pushing them, staggering ear drums, pure dread
bursting in scatterflash and stuttercrack, these terminal fireworks
at odds with all past knowledge. So the beat goes on, no end to it,
and in this Thomas Hardy sky you'd see, had you eyes for it, words
like numb and wasting inscribed, and sad or dim, drearisome, wan,
and everything tucked in like a heart in its beating chest of bone
so the whole body thrums with it, beaten through and through by it.
(Thomas Hardy--he was great; I didn't know junco--it is apparently a kind of finch).