Web4 is about making connections, about serendipity and about the network taking initiative.
Some deliberately provocative examples:
I'm typing an email to someone, and we're brainstorming about doing a business development deal with Apple. A little window pops up and lets me know that David over in our Tucscon office is already having a similar conversation with Apple and perhaps we should coordinate.
I'm booked on a flight from Toledo to Seattle. It's cancelled. My phone knows that I'm on the flight, knows that it's cancelled and knows what flights I should consider instead. It uses semantic data but it also has permission to interrupt me and tell me about it. Much more important, it knows what my colleagues are doing in response to this event and tells me. 'Follow me' gets a lot easier. Google watches what I search. It watches what other people like me search. Every day, it shows me things I ought to be searching for that I'm not. And it introduces me to people who are searching for what I'm searching for.
Seth listed a bunch more. All are great ideas, and undoubtedly be useful to some people, some of the time. But that's just it. These ideas are ONLY valueable to some people some of the time. Maybe I want David in the Tuscon office to know what I'm doing, but maybe I don't. Perhaps what I'm doing is confidential per my company President. Perhaps I'm working with them on an IP issue and David is talking to them about who their favorite paper supplier is. How does web 4.0 know all this? Under anything resembling current models, it doesn't.
So that means that I would need to go into all my devices and setup an increasingly complex permissionings system to account for hundreds (perhaps thousands) of situations. The alternative is for me to set all these permissionings to default, which means that I'll be receiving too many messages I don't want, and sending out more information than I'm comfortable with.
The part about collecting the data is easy. What's hard is setting up the permissioning process so that you can make use of the data...
Btw, my old friend Mike Song just published a book geared towards helping us make sense of our digital choices. I'm sure it's worth reading...