Mountain Hardwear has a new pack, the largest I'm aware of with a vest-like shoulder harness. Could be an interesting option for multi-day running, as well as scrambling and general fast and lightitude. Claimed weight of 12 oz.
I've been using the Thruway 50 all year, and am just about ready to finalize the review. It's a mixed bag, but MH is taking a more aggressive approach to pack design, for which I applaud them.