It would be great to get a series on one or two disks instead of these huge boxes.
Who would use them? Serious question.
Netflix likely won't adopt any future disc standards for the disc side of their business. Blu-ray is already an additional charge, and they've made it very clear that they view that side of their business as a dying, legacy one, and they even made an effort to divest themselves of it back when they tried to split it off a few years back. Storefront video rentals are nearly extinct, with Redbox and digital distribution displacing them, and Redbox certainly won't be offering whole series anytime soon, since it makes no sense for them to do so. For movies, blu-rays already serve all of their needs. In other words, there's no market for AD rentals.
I suppose Amazon and other retailers may sell the discs, but who would buy them? Hardcore collectors, sure, but outside that niche? The way I see it, you primarily have two types of folks:
1) The folks already using blu-ray. Theoretically, AD would draw primarily from this group, since they are the ones who would care about any benefits it has to offer, but it seems to me that its primary benefit is easier distribution than blu-ray, which is something that digital distribution already deals with for most people, and it's already being adopted by this group as the next step beyond blu-ray. As for content availability, most people would prefer to purchase a few extra blu-rays during a transitional period to the digital distribution that they've already started adopting, rather than investing in an entirely new format so that their shelves will be a bit tidier.
2) The ones who have to be dragged forward. They're the ones still using DVDs and who will only upgrade when they are forced to do so. Since AD players are likely to be backwards compatible with DVDs, these people will see no reason to purchase anything more expensive than DVDs, which, as is the case today with blu-rays already on the market, will keep the market for DVDs alive and healthy. They'll never upgrade to AD, since AD isn't forcing them to upgrade in the same way that DVD forced them to upgrade from VHS.
Really, the only use I see for these discs is...wait for it...archiving. Assuming they have a decent shelf life, I could see these replacing, or at least supplementing, the backup tapes that are still widely used in business settings.