AR without markers would be huge. That means it could be integrated into a seamless experience. Simply from an advertisement stand point, this is huge, as they wouldn't have to pump out new ads for it work.
From a consumer stand point, this would be even better. We'd finally be able to leave our phones in our pockets (where phones are destined to be), accessing it through menus we envision on our arm or hand. We could watch video anywhere. And if coupled with technology like WiFi-Direct, we could all enjoy watching the same video. Even better though, imagine it being able to access someone else's camera and see what they see. That's not AR, but easily the best side-effect of it.
Actually the best side-effect of AR would be recording my drunken escapades. If the glasses are as pimp as the one
DARPA is making then I'd rock them all night. And what's even better, it could tag people and places that I met and been to automatically, so when I look back through the video I could look at outline and skip forward to an exact moment.
So yeah, simply having the glasses is much better than using your phone.