I would love to buy a medium-capacity handlebar bag that (1) straps to
the handlebars (requires no rack, hangs down close to steering axis),
and (2) has a couple of pockets facing the rider that can be accessed
while riding. Something like a (smaller) version of the old Baggins
Hobo bag, which seems to still be in demand, at least among members of
this forum.
My ideal bag would be a design like Acorn's medium handlebar bag, made
with Rivendell's current excellent waxed canvas.
Rivendell already offers several nice handlebar bags, and I'm sure
they have their hands full with other products in development. But I
would certainly buy this handlebar bag if it existed. There's another
thread going in which someone is looking for a bag for Bullmoose bars,
I bet a Hobo-style bag would work for those too.