Until now, the only info I had heard on the new GoLite Peak backpack (little brother to the Jam) is from the BPL coverage at the outdoor retailer show which didn't say much more than the weight (27oz) and the size (2300 cubic inches).
This evening I read a few more details which shed some light on the surprisingly heavy weight here:
http://www.campist.com/archives/golite-peak-backpack-2010.html
Of interest is that the hipbelt is actually detachable. That's sure to save a lot of weight by leaving it at home since the hipbelt includes pockets. Also, the backpad is detachable too which likely saves 1-2oz if you don't need it. This pack could be a lot more tempting than I initially thought. There's a good chance it's sub 20oz with these things detached and you could save another 2oz by removing the hydration bladder and trimming the straps.

