Walled gardens and a "protectionist web" are the natural outcome of the legal structure we've chosen to put up around the internet. It's not a technical limitation, and technical solutions can not really affect it.
Just this week there was a "Show HN" that combined data from Twitter et al in interesting ways. It was offline less than 24 hours later as all the comments indicated that it was a clear violation of the policies of various content providers.
Why should we care about those policies? Well, because under the CFAA, we've made it a federal crime to send packets to a server in a way that displeases the server's owner.
There is no technical limitation stopping people from collecting and curating data from many sources and combining/filtering them according to their own interest. The internet is already open in principle (cue Schneier: "trying to make digital bits not copiable is like trying to make water not wet"). The issue is that we've given the Facebooks and Googles of the world the right to hold our data and our personal networks hostage.
Start a decentralized, standardized protocol like email or IRC and companies will cooperate insofar as they must to ride the wave, and then they will work aggressively to corner things off into their own little world.
Understand, all software companies want one thing: lock-in. They want to make it so that there is as much pressure as possible to remain on their platform. It's the age-old story of someone who can't move to Mac, even though they greatly envy it, because their greeting card program from 1997 won't work on it. Instead of importable programs, it's importable personal networks -- but now, with everything server-side, it's usually illegal to try to bridge that gap on the user's behalf (insofar as doing so involves contacting the server of a competitor).
The situation with potential copyright and patent violations was precarious enough when it was all occurring on the user's local machine (WINE is in a big legal grey area, for example; my instinct is WINE would lose if MS ever decided to seriously try to squash them), but once you cross the line into some company's IP space, all bets are off. The CFAA allows them to define "authorized access" to their servers on their own terms, including "people trying to access our server to provide data portability". This has already been litigated with specific regard to Facebook in Facebook v. Power Ventures.
As long as we give companies the legal tools to exert effective ownership over user-generated data, we are destined to see well-designed, decentralized protocols that maximize availability, resiliency, and portability get whittled away by the overriding corporate interest in establishing some element that can be used to keep users locked in.
The Halloween memos may have caused a stir in the late 90s, and they're all but forgotten now, but their sentiment is more alive than ever.