They will quickly pass this, mostly true information, on to other members of the cognitive elite. This means that the higher pace of information dissemination will translate into a higher pace of learning true ideas, for this group.
But spreading information is not the only reason why people communicate with each other and make statements. In some cases it isn't even the most important one.
I used to follow a local politician on Facebook and read his blog. A few years ago, before he was elected, he used to post interesting ideas. Over the next few years he became more popular and eventually he was elected to a city's council. Nowadays his facebook feed consists mosty of photos of him participating in various events, meeting local business owners, visiting municipal utility companies and so on. The whole feed is photos of people smiling and he basically never posts his ideas anymore, unless they are obvious applause lights. Oh, and he stopped blogging. I don't blame him, because his political persona is based on being liked by anyone and not being polarizing.
Of course, this is an extreme case, but many people have their coworkers and bosses on their facebook. And being polarizing is rarely the best way to advance your career. It seems that only young people care about spreading ideas (good or bad) on their facebook feeds, older people usually prioritize different things when posting on facebook. When you are young it is easy to find new friends, therefore it is not a big deal if some people do not like what you post. When you are older, finding new friends is much more difficult and keeping the old ones becomes much more important. Maybe that's why in my experience older people tend to post different things than young.
I think it does among the cognitive elite, and that this explains the rise of complex but good ideas such as applied rationality and Effective altruism. I'm less sure about other groups.
The Internet increases the speed and the convenience of communication vastly. It also makes it much easier for people with shared interests to get in contact.
This will of course lead to a tremendous increase in the amount of false or useless information. But it will also lead to an increase in true and relevant information.
Now members of the cognitive elite are, or so I claim, reasonably good at distinguishing between good and bad ideas. They do this not the least by finding reliable sources. They will quickly pass this, mostly true information, on to other members of the cognitive elite. This means that the higher pace of information dissemination will translate into a higher pace of learning true ideas, for this group.
What about non-elite groups? I'm not sure. On the one hand, they are, by definition, not as good at distinguishing between good and bad ideas. On the other hand, they are likely to be heavily influenced by the cognitive elite, especially in the longer run.
By and large, I think we have cause for optimism, though: good ideas will continue to spread quickly. How could we make them spread even quicker?The most obvious solution is to increase the reliability of information. Notice that while information technology has made it much more convenient to share information quickly, it hasn't increased the reliability of information.
There are a couple of ways of addressing this problem. One is better reputation/karma systems. That would both incentivize people to disseminate true and relevant information, and make it easier to find true and relevant information. (An alternative, and to my mind interesting, version is reputation systems where the scores aren't produced by users, but rather by verified experts.)
Another method is automatic quality-control of information (e.g. fact-checking). Google have done some work on this, but still, it is in its infancy. It'll be interesting to follow the development in this area in the years to come.