So here's what I've gotten from it so far:
#32, from as much as I've read of it so far, seems to be an explanation of Alan Moore's personal philosophy on how magic, language and consciousness are put together and inter-related. I guess you could read it on its own since it doesn't pick up any plot threads from previous issues, but the entire series is worth checking out, too.
And I just now got done reading the whole issue for the first time. There is an editor's note about the format of the book on the inside-front cover which states that you can read the book in the order it's bound of fold it out. The book was laid out so that it made a large, double-sided poster, then it was cut up for periodical form so that they could ship it easier. Viewing the comic, the first 16 pages are on the front side of the poster and the final 16 pages are on the backside. If you pick it up, be sure to tear it apart and tape it together in poster form, because a) you'll be flipping the book all over the place to get to the "pages" in order (they're numbered according to the 32 paths of the Tarot) and b) it's a really interesting/fun way to read a comic.
In poster form, but book is very much like something Scott McCloud would do with an infinite canvas. You can either read the pages according to Tarot number order (left to right, top to bottom) or you can kind of follow the trails around and read the notes in a sort of random order. Oh yeah, the notes (mentioned below) are semi-connected by trails of stars and ankhs which criss-cross the whole poster.
In all honesty, the script is basically an essay with additional notes which explain some of what Alan Moore is talking about and the art is mostly just there to keep your attention and provide some of the visual data relating to the notes. The Promethea character is nearly invisible on the pages and mostly serves as a focal point for the script, which is in word balloons (the notes are in differently bordered, circular captions).
I dunno. While it's an interesting read, Promethea #32 seems to serve mostly as a footnote to the rest of the series (which really ended with #31, I'd say, since that issue was the aftermath of the apocalypse.. plus, the title of #32 is "Wrap Party") and as a kind of "hey, go try new things" from Moore.
Back to the poster premise; since this issue is mostly an essay, the poster format works, being that there's no story to really follow. I don't think this format would work too well for a structured, conventional comics story because your eyes would be too prone to jump around the poster. If the story was written and drawn along the lines of the story from page 84 of Understanding Comics, or maybe one of Scott McCloud's, Drew Weing's or demian5's crazy webcomics (the ones that scroll all over the place), it could work.