This is a big change for HBO, which is usually incredibly protective of its content.
The pattern for HBO, traditionally, is one of content protection. Their goal is to get you to subscribe, and they do that by making sure that HBO is the only place you can see their original programming. That, or you can pay for the series on Blu-ray, the price of which is typically far above the norm.
Louis CK's new comedy special is a change for the company. HBO will be airing CK's standup initially, but "a few months after," it will be available everywhere around the world for just $5 with no digital rights management attached. Pay your five bucks and you get the file to do whatever you want with.
This isn't the first time CK has offered a DRM-free version of his standup, but this instance is unique in that it pairs with the typically protective HBO.