Originally, this was going to be about human language, but I had to build up too much of a computer-protocol backstory. So now it's about computer protocols. Maybe I'll do the human language one later.
Protocols evolve as the requirements change. Early computer-to-computer protocols were simply transferring bits and bytes wholesale. This worked because there wasn't as much traffic and all the sharing computers ran the same operating system and understood bits in the same way.
As time passed, we evolved dozens of more specialized protocols. Nearly every computer has most of the same protocols even if it runs completely different operating systems. We all access the internet, we all read text files, we all view images. There are differences: EOL characters, for example. But, for the most part, these protocols allow our computers to trade information transparently, without needing to even know what kind of system we're talking to.
The reason I'm rambling on like this is actually fairly straightforward. Computers have fundamentally changed how humans can gather and think about data. Protocols help that along. We need (and will get) better protocols.
We see the problem in email protocols. Email protocols were designed back in the early days, before the internet was really an "open" place. Therefore, they didn't worry much about contexts and limits and so on. So today, most of the email on the internet is blind-mailed spam. Most of the rest is unwanted but targeted spam, such as my continuous emails from Amazon.com telling me I want a Kindle or the newest book from Oprah's list, both of which I despise. Email is "sort of" efficient in that it seems efficient to us, but only because we aren't aware of the poor performance it's actually giving us. Sort of like a skateboard feels efficient until you get on a bike, and a bike feels efficient until you drive a car.
New email protocols have been discussed. A lot of people have talked about doing things like charging a tenth of a penny per sent email. But changing the email protocol is almost impossible, sort of like trying to replace a jet engine in mid flight. Personally, I think the answer is easier than that: I think email is on its way out. We don't need to replace the jet engine, because the jet is going to land safely at its destination and we're all going to get off.
That whole method of conversation, that whole protocol, is going to fade away. It's going to be replaced be feeders. RSS feeds, Twitter feeds, and new kinds of feeds that haven't really been invented yet. Feeds are a high-context pseudo-whitelist system that minimizes unwanted spam and maximizes comprehension.
These next generation feeds are going to radically increase the amount of context a message contains. If someone Twitters "I like these shoes!", we see the thread back to the shoes. Not an embedded link, exactly. A context thread. If we visit the shoes, we'll see threads lancing "forward" from them to people who have talked about them, and threads lancing "backwards" to things like shipping information, company information, who makes the shoes in what nation, and so on.
This is not something that is easy to imagine if you try to stuff it into today's linear, square-screen environment. Instead, throw that image away and try to think of something entirely different.
I don't know exactly what the dominant interface will look like. Perhaps some kind of mouseover-friendly "constellation" feeling. Perhaps it will be bullet points, and the computer will quickly give details about each in series, highlighting your salient concerns. Perhaps it will be more like a river, with contextualized information flowing rapidly by, random pieces flipping up to give you a feeling for the overall flow. I don't know. But the point is to think wonky, not to think of an evolution of today's displays.
We're talking about a fundamental change from a 1D system of information gathering and display to a much more complex system of information gathering and display. The tree of interconnectivity and context will grow faster and faster and faster, become more and more automated. This is not 1D by any stretch of the imagination, and even now our web pages fracture under the strain, separating into menus and sidebars and ads and last-posted links and and and. If you think this is a good way to display data, you're wrong. It's got to be replaced.
This complexity hasn't much leaked into email, which is actually bad. The fracturing is not a bad progression. It is simply growth pains. Our experience has gotten more interactive, higher context, faster communication. If we reach our news front page and we know how it works, we can see all of today's news quickly lined up, and instantly navigate in if we want more detail. Much more efficient than newspapers, certainly. We've gotten very efficient at navigating the web due to this fracturing.
More efficient with everything except how we, as actual people, talk to other people, as actual people. IE, personal emails and communications.
That seems like the most important kind of communication to me. And I think the next generation of protocols, the next big method we use to interact with each other, will replace email. Replace it with something much deeper, much higher-context. And, hopefully, much less prone to spam.