SKD has the new Camelbak 500D Cordura line available. Anybody got the new Motherlode or BFM yet? I was planning on getting one of those two this month. Any major differences between the two beside the external side pockets?

Can't speak of either of those, but for the HAWG, which I picked up to check to see if I wanted to carry that line, they made it a little bigger and added a top pocket lined with microfleece.  I suspect the BFM and ML have a similar added pocket, if my recollection from 2008 SHOT is correct, plus they'll be a bit bigger in capacity.

Instead of making the packs the same size, but lightening the weight due to the difference between 500D and 1000D, it appears they made them a little bigger for the same weight as the 1000D packs.

IIRC, the BFM is bigger by something like 400cc, and about 1lb lighter than the standard pack

I picked up one of the Ambush 500D's.  It's pretty damn fantastic.