I agree. Most information doesn't need to be learned in realtime, just made available in realtime. If you need data, you should be able to find it. If you don't need it, it shouldn't command your valuable attention.

Email lets each participant manage their attention according to their priorities. If you're arm-deep in refactoring a class hierarchy, you don't want me to call, especially if I just want to blather about hockey. Email also feels more scalable than instant messenger - I asynchronously communicate with more than a dozen people every few hours with email, but IMing or texting starts to feel overwhelming at n >= 5