A commit that was discovered by the Chrome Story team suggest that Chrome OS could have the ability for administrators to sideload Android apps on devices. Currently the only way you can sideload an APK to a Chromebook is if the device is in Developer Mode. That mode essentially bypasses all of the Google security measures like boot loader verification.
If this Commit makes it through the gauntlet and arrives on Chrome OS, there would be a mechanism by which administrators could load apps that are not in the Google Play Store, currently the only way to install apps outside of the afore mentioned Developer Mode. For now, it appears that this would only be an Enterprise level administrator feature in the platform.
The benefits on this are pretty big. It would allow organizations and schools to load applications onto Chromebooks without having to go through the process of publishing them to the Google Play Store. Companies may not want to do that if they are have homegrown an app that deals with proprietary company information as an example.
There is no estimated time on when or if this will make it into Chrome OS but considering it is marked as a work in progress and was updated just last Friday, chances are good that it is on its way in the next beta or two. The bigger question is if this will make it to the consumer builds of Chrome OS. That is very much a TBD at this point.