Inspired by the comments on Rooftopper Rav's Jewschool post complaining about the Artscroll Women's Siddur, I've decided to write down what I think it is I want in a new siddur. The target audience of this siddur, I think, would be slightly different than that of all existing siddurim. So here we go:
It should be a "kol bo" siddur, which apparently means "shabbat and holidays and weekdays". I certainly don't need high holiday stuff rolled in.
Except, maybe it should leave out things that are found in any good bentcher? A lot of the suggestions below serve to increase the size of the entire venture, and this might be one way to save some space. Though I'm flexible on this point.
Page layout should be unforgiving. Cram everything together, like Artscroll. Or at least like Sim Shalom. But not like Kol Haneshamah or Purple. We're going for utility here.
Page size and binding should be like Sim Shalom and Artscroll. Pages around 6"x9" or whatever those are, very lightweight paper, perfect-bound. One main thing that's missing from The Purple Siddur and The Yellow Siddur is portability. So how can this slimming down be accomplished?
It should have less than everything transliterated. Purple and Yellow were both revolutionary. And I love Purple. (I don't feel the same way about Yellow, but that's because it's targeted at an audience I'm not a part of.) But I think they've created a trap that all of us liberal siddur brainstormers fall into. Transliterating everything creates a much weightier siddur, not to mention creating massive layout headaches unless you use unnaturally large page sizes. And since we're going for a slightly different target audience here, I'm okay with getting rid of the 100% transliteration. However, I don't know whether some things should be transliterated or not. If you don't transliterate anything, you lose the ability to rope in some less experienced daveners with poor Hebrew skills, since they won't be able to sing along to anything. But if you transliterate some things, you're being normative about which things "are sung" and which aren't. Also, if you do transliterate, do you squeeze it in on the English side of the page like in New Sim Shalom? Maybe you do an interlinear transliteration in the Hebrew? Or would that be too distracting?
Oh, by the way, facing English and Hebrew pages should have the same page numbers. Lots of siddurim are getting this right these days. People calling or writing page numbers shouldn't need to be normative about which version of the prayer they're indicating.
It should have interesting kavanot on occasion. Maybe below a horizontal line on a page or something. I'm not so into that sort of thing, but I know some people are, and kavanot don't hurt anything. However...
It should have literal translations. Nothing frustrates me about Sim Shalom more than poetic "translations" of poetic bits of liturgy, when the "translation" is more like a poem inspired by the original. There are better poetic translations of things out there, but there's a time and place for that sort of thing, and I don't think this prayerbook is it. Unless such inspired work is located as a kavanah on the page in addition to a literal translation.
It should be liberally footnoted. (Can you tell I'm trying to encroach into Artscroll's territory here?) I want to know the source of every text in there. I want to know the translator of everything. It really wouldn't take up that much space.
Here's the big one: It should have lots of pluralistic, non-normative stage directions, also liberally footnoted. "In some communities, everyone stands for this kaddish; in other communities, only people reciting kaddish stand." "Some communities discourage women from reciting kaddish, but many encourage it." If you want to know more, read the footnote, maybe check out the sources, and make your own decisions on what to do. I know of no siddur that guides people to making their own decisions on this sort of thing, informed by knowing the source of whatever practice they're questioning.
It should contain alternate texts and wordings, and clearly distinguish somehow which alternates are for occasions and which are historical or modern changes in text. The challenge here is to come up with some way of making "some people say the imahot" and "most people say this line, but only on shabbat shuvah" visually distinct. Using brackets or small font for both of them won't cut it. And in the case of text changes not occasioned by the calendar or life cycle events, where there's an addition that's clearly non-normative (such as including "v'al kol yoshvei teivel" in the first line of "shalom rav"), I do think it's fine to "diminish" the alternate version by putting it in brackets or a different color or something. But footnote it! But where there are slightly larger text changes, or when there are two widely-used versions of something (like with Yedid Nefesh), it's fine to have "page 156a" and "page 156b". This way the siddur is both letting individuals choose between them and letting page-number-callers decide whether to announce a particular version of a page or just a number.
So, an example of all of this: Aleinu. I'm envisioning two dapim. The first pair of facing pages, page 678a or whatever, has the traditional text, with the "shehem mishtachavim" half-sentence in brackets or small font or something, endnoted. (The note would be 1-2 sentences long, indicating the time period that line was removed, why, and perhaps a source for more information.) Page 678b would have an alternate, modern version of the first paragraph, with authorship and reason for replacement noted in the endnote. It would also have the second paragraph, so people don't have to flip back. On both pages, the first half of the first paragraph and the last line of the second might be transliterated, and the whole thing would be translated. Perhaps both pages would also footnote the entire prayer, indicating that it came from the high holiday liturgy and began being used for daily services in whatever century.
So make hardbound and mini-softbound-pocket editions, cram the weekday torah readings into the back of the pocket one, and we're done!
What do y'all think? Am I missing anything? Who wants to make it with me?