Ok, just talked to Osprey, and the new packs are expected to hit retail stores in mid January. The Poco series will feature three packs, with the lightest of them at 5 pounds 7 ounces. I don't have any information on other features, such as storage, but here is the basic description of these packs from the OutDoor fair in Germany where they were first introduced:
Poco - Osprey’s new, highly innovative Child Carrier
Light on the back, comfortable to wear, and containing clever safety features: Osprey’s new child carrier is launched after three years of innovative development. With a height-adjustable saddle, ventilated and fast-adjustable backsystem, harness and hipbelt, the Poco demonstrates high comfort. Thanks to the rounded Aluminium Frames with a lockable base containing injection moulded hinges, the free stand is stable and safe.
In comparison, Sherpani states the weight is 4 pounds 12 ounces, which i think can be reduced further by removing the useless straps for legs and the roof.
Deuter Comfort II is 6 pnds 1 oz.
Interestingly, I also found another baby carrier on the OutDoor's product list, called VAUDE Child Carrier Wallaby:
Ultralight and Earth-friendly VAUDE Child Carrier Wallaby - bluesign approved
The world’s first child carrier according the bluesign® standard is a masterpiece in
design and technology. The new VAUDE Wallaby combines stability at a very low
weight (1.8 kg), with secure performance and ecological materials. All components
have been tested for maximal safety according to the bluesign® standard – safe for
both carrier and child. The support base locks securely into place and can be folded in.
i would go with this last one if only they were available in the US!