For the early adopters among you, the QD module end is a discrete part so Magpul could release the dongle end as an accessory. But, I'm guessing that end of the sling makes up the lion's share of the sling's cost; what with the QD, Magpul's paraclip loop and all the sewing going on at that end. So, the angry old man in me thinks Magpul won't bother putting out an accessory SKU for an item that will cost 50-75% of a whole sling. The QD version adds $8 to the MSRP of the original MS2 of $50.
In any event, it's good to finally see an MS3 for the other half. This sling has really grown on me. The MS3 really addressees all the issues that kept the MS2 from taking off. The nasty tubular webbing, the funky metal clips, etc. The new sling is comfortable, works well and so far, has no durability issues. More specs are available at magpul.com.