It seems to me, my friends, that we are sliding along here, achieving comprehension without achieving translation.
What have we got? To begin with, it's lovely "bupmty-bumpty" verse. This isn't Virgil, and even peasants (like myself) can hear the music straightaway.
The idea that classical weight-based meters are normative in Latin is, I think, an unfortunate error, arising from the narrow, classically-confined curriculum that is what we too often feed students today. Those meters aren't really Latin in the first place, but Greek (just as the "French Forms"-- the triolet, for example- aren't really English, though a great deal of great verse has admittedly been achieved by the use of the foreign forms in the new tongue).
And neither stress-meter nor rhyme in Latin verse is confined to to our current scurrilous genre. Look at the De Contemptu Mundi of Bernard of Cluny, 150 years or so before our present example, or look to many of the magnificent hymns and sequences of the high middle ages. Some of these were still regularly sung when I was a boy, and some still give me goose bumps if I'm lucky enough to hear them today. Imagine (those of you too young yourselves to remember) a cold night in a dark church, lit only by a couple of candles and maybe a little moonlight, as one single voice, way in the back, begins to sing words 600 years old:
Dies iræ! dies illa
Solvet sæclum in favilla
Teste David cum Sibylla!
Quantus tremor est futurus,
quando judex est venturus,
cuncta stricte discussurus!
Or on a happier note, this of Aquinas:
In supremae nocte coenae
Recumbens cum fratribus,
Observata lege plene
Cibis in legalibus,
Cibum turbae duodenae
Se dat Suis manibus.
But I digress. What have we got? This is stress-meter trochaic tetrameter, not a common meter in English, but not unknown-- think of Poe's The Raven. The 6th and 8th lines diverge from this, being of but four syllables each. The rhyme-scheme is AAAAABAB, with the A's being feminine rhymes, and the B's, as I think qmf pointed out, being pseudorhymes.
Our task as translators (as I see it) is to reproduce this music while doing as little violence as possible to the meaning; to echo the sound while maintaining the sense. This should be relatively easy here, there being relatively little sense to maintain.
Let's try this for the first stanza:
Drinkers to the art attaining!
Thirst's allowed without abstaining!
Ye who swift the cups are draining,
Never another round disdaining,
Lines of empties proud maintaining,
-----Just keep 'em coming.
Wits who'd be entertaining?
-----A background humming!
Now I think there's a lot wrong with this. But I'm dumping it here as a point of departure.