One of the old school projects I'm most looking forward to seeing completed is JB's B/X Companion, an attempt to create the mythical third volume to the Moldvay-Cook-Marsh D&D rules, based on hints in the books we do have and healthy doses of imagination. As a younger person, I remember anxiously waiting for the release of that volume and was greatly disappointed we never saw it. Granted, we did, eventually, get a Companion set -- I even liked it -- but it wasn't quite the fulfillment of my earlier dreams and so I still long for a Companion that's more in the spirit of the B/X rules rather than the later ones.
What especially impresses me about JB's project is that he's keeping a 64-page limit on his work. To me, a relatively low pagecount is essential if your goal is to imitate the style of the early 80s. Indeed, I'm slowly coming round to the notion that one of the oft-overlooked aspects of old school design is page length. With the noteworthy exception of AD&D, whose position is problematic on a number of levels, most rules sets from the Golden Age are quite compact and concise. Not all of them are under 64 pages, it's true -- and in any case I don't want to be misconstrued as saying "anything over 64 pages in length isn't old school" -- but I do think that short and sweet is a defining characteristic of the Old Ways. It's why I continue to insist that there are "structural" aspects to old school design, contrary to the "old school is a feeling" crowd.
In any case, I very much look forward to seeing the B/X Companion finished and released. JB's decisions will undoubtedly be different than my own would have been, but I do think he's on the right track in trying to keep the rules short enough to fit within 64 pages. That's a design principle I'd love to see more RPGs of all sorts emulate.