There is one benefit to the per-encounter design philosophy that adult gamers will come to find useful: it allows for meaningful progression in smaller, but more frequent, episodes. In other words, regular short gaming sessions become viable. You get online, you play through one or two encounters in an hour or so, and you call it a night. Still have plenty of time to watch your favorite shows, spend time with the wife and kids, run off to that choir practice at church, or whatever else takes up your time after that and yet you maintain your presence as an active gamer. This style of design and play is more convenient, more casual-friendly, than the current or older designs.
Again, as the industry greys, the games will begin to drift from their service to people with no money but lots of time, to people who have lots of money but no time. If WotC did what they've promised, expect a lot of the load to be taken off the DM's back, especially in terms of preparation for the game, and running combats. How well this works remains to be seen, but I imagine it will be a the make-or-break deal for a lot of older gamers.