Google announces plans for support Android-Like web intents in Chrome. I think it is very interesting solution.
Intents allow two separate applications to communicate with each other, without either of them having to actually know what the other one is. Instead, they offer and listen for generic hooks.
It means, for example, that a new photo hosting site could easily integrate editing functionality from existing photo-editors, without either of those services needing to implement a special API unique to that photo editor site.
This is an incredibly cool idea that essentially brings back the concept of a decentralized web. By the way, I think custom URL schemes like: mailto:, tel:, sms:, twitter: (on iPhone) are like lightweight intents. For example, wee can add link for sending SMS without knowing how that functionality is implemented.
Btw, one of interesting area intents should be good for is M2M. What is we need to add some new M2M device to our system? It is almost no way to redevelop system for the each new device (new API). With Intents we should be able to describe (add) new devices (new measurements) without deep dive into new programming. The future for M2M is here.