I for one am hoping that this catches on, walled garden or not I'd rather spend my time reading content on an interface that I don't have to fight against (e.g. full screen overlay ads with a tiny x to close) and I trust facebook to build that better than anyone else.
I'm also surprised publishers are going along with it though, it seems a little ironic. The only reason this product is interesting is because so many mobile articles today have horrible UIs. Native views will probably be nicer anyway but publishers could mostly fix this right now if they were willing to give up my accidental ad clicks. But instead they need someone like facebook to save them from themselves in order to make their content consumable again.
By the way, there is an extension that removes overlays on any website and doesn't require any permissions, Behind The Overlay => https://chrome.google.com/webstore/detail/behindtheoverlay/l...
It's activated by clicking the icon or by using a keyboard shortcut (cmd+shit+x). So there is at least one single way to close any overlay on any website.
And, no, I don't feel guilty - I might have felt guilty if I only paid for ads with my attention (I'm not sure though - I don't feel guilty ignoring the ads on a print newspaper). But allowing ads through means you give 20 or so organizations with questionable ethics complete info about your web use, including (but not limited) to when and what -- and those 20 organizations sell that info to the highest bidder. No, I don't feel guilty at all.