I've considered this, and I think only mild partitioning would be effective. For example, separating Instagram from facebook instead of integrating it further. This would do nothing to the site itself, though.
My solution would be to have facebook be more willing to work with other social networking sites. Right now facebook is like a telephone company that only allows folks to talk to others on the same network.
Minimally, the chat programs would need to communicate with each other, even if they didn't share all features (still needs to be very useful). Further changes would be things like allowing other social networks to view "public" things one posts or being able to friend across platforms.
This is unlikely to happen, though, if it is possible at all. I'm assuming that a standard would need to be agreed upon and they'll be quite the fight from facebook. Not to mention the sheer amount of work it would involve upfront or at least I'm assuming, as I'm one of the non-tech folks that are reading here.