The Galaxy S8 isn't Daydream-Ready but it might be one day. There is nothing so far to suggest that Google and Samsung are working something out to allow this compatibility, and Samsung certainly doesn't need Daydream support on this phone since they already offer their own mobile VR platform with the Gear VR, but the Galaxy S8 is more than capable of handling the content that Daydream can throw at it thanks to specs like the 4GB of RAM, the Qualcomm Snapdragon 835 or Exynos 8895 processor depending on where you buy the phone, and the large as well as nearly bezel-free Infinity Display.
While the Galaxy S8 and Galaxy S8+ may never officially get support for Daydream like the recently made Daydream-ready Huawei Mate 9 Pro and Mate 9 Porsche Design, but that won't always be a problem. Once the Galaxy S8 and Galaxy S8+ are capable of being rooted it will be possible for eager users to alter the code of the system permission to allow Daydream to become compatible, and from there it's as simple as installing the Daydream app and then installing apps for the platform, like Netflix VR, Need For Speed No Limits VR and others.
Until then, users with either of these new phones, once they actually launch in April, will be limited to using Samsung's Gear VR headset which is powered by the Oculus software. While this prevents users from accessing any of the Daydream apps that reside in the Play Store which may not be available on Gear VR, the Gear VR platform has a fairly robust offering of apps and games already so users won't be without a hefty set of options to check out some virtual reality content. That being said, if the Galaxy S8 and Galaxy S8+ eventually did get official support for Daydream it would give consumers a lot more choice and would only benefit both Samsung and Google, as they would both be able to reach even more consumers who may consider the worlds of virtual reality and all that they have to offer. If you do want to experience VR but you also want the Galaxy S8, Samsung's new Gear VR controller with the Gear VR headset should allow for a similar experience to Daydream in regards to the interaction once the controller launches on April 21st.