They will be effective in the short term, and then drop right down to where traditional ad banners are now. It's just a gimmick, frankly, and while they may be able to get a few more clicks from a few users, they ultimately won't engage any additional traffic. That's just not the case. The problem comes from trying to insert a commercial message into a focused user task. Of course not.
Advertising does work, but only when the context matches the user's goals.
I can't imagine they're here to stay. It's just an elaborate and desperate attempt to get a few more clicks. I don't want deep interaction with a sliver of the page. And I certainly don't want audio streaming out of an advertisement. I've already mentioned that advertising has to be consistent with the user experience.