You could imagine Adobe following suit very shortly here withs something similar and invalidate all those graphic/template/icon/texture/animation sites. You just open the "marketplace" inside of Photoshop and browse around for the assets you might want.
Same would go for video-editing. No more buying Action Essentials, just load up Final Cut and look for the perfect blood animation.
You could imagine at some point your IDE having a marketplace inside of it to allow you to purchase proprietary platforms directly and integrate them into your project without much hassle.
It's a really cool proposition, ripe for monopolization unfortunately, but surely convenient if executed on well.