We publish new information almost every day at SQLServerCentral. When we do re-publish an older piece, it's usually after a year has passed from the original publication date, and we often find many people have never seen the article before. For them, the article is new. We also find that people who have read the piece find the re-publication to be a reminder of that particular topic. In either case, our goal is that you improve your skills with SQL Server, learning to better manage an instance or to write better code.
No matter how you take the information we publish, or anything you learn, I find that many people are torn between two choices. They can continue working with their existing knowledge and solving problems relatively quickly, or they can adopt a new technique immediately. If they choose the latter, they might work slower as they develop some skill and gain new understanding. They might even re-factor existing code to use their new found knowledge, which takes time.
The hard part for many people can be in making this decision about whether to use new knowledge or stick with existing techniques. If there's a dramatic reduction in resource usage from new code, then that's an easy decision. However what about those cases where the increased efficiency is limited? How do you decide if new knowledge is worth "deploying" or "holding"?
Personally I think new knowledge should be added to your toolbelt, and experimented with. There are no magic bullets that solve all your problems in a domain. You should use the skills you allow you to solve problems quickly and confidently, but you should also be experimenting and practicing with new techniques. Over time, your work will evolve and improve as you develop more ways to solve problems and learn to choose the appropriate solution for each particular problem.