There has been a lot of talk and excitement in the Linux/Ubuntu community about the Unity 8 desktop preview. Basically, Unity is the graphical "look" of Ubuntu. I didn't realize how badly we needed a modernized revamp until I saw it myself. I currently run Ubuntu 16.04.2 LTS with Unity 7. "LTS" stands for "Long-term support" in which this version will get at least 5 years of security and maintenance updates until developers shift their focus to the next LTS version. So now we can look into the improvements and changes between Unity 7 and the Unity 8 preview!
A few of the outright changes include flattening the design of the interface and removing gradients. The default background has even changed from a very soft gradient flow to a sharper, fragmented image with similar colors. This is expected as style has gotten more minimalist in OS/Application design again.
Another large change is the (kind of) removal of the task bar. It still exists, but there is now another graphical way to interact with apps - Scoops. This is a mobile-like app launcher that acts as a window more than an anchored utility. I'm personally uneasy about this decision, but we'll see. There is most likely going to be a built in app launcher as this is so early in development - things change.
Lock screen images are hard to find as the lock screen is still really buggy, but there is only one big graphical change. Unity 7 has a dot-matrix pattern overlaid over the image while Unity 8 seems to have a circular widget that says "no photos taken today." I'm interested to see what this means in upcoming updates.
Unity 8 has a long way to go before it is stable, and unfortunately I think it will probably not be consumer ready for the October 13th Ubuntu 16.10 update. It is very nice to see progress has been done, though. All of this new information has sparked debate and conversations about the direction and theories of programming and design that the open source community must make. Demos are available easily through a simp[le terminal install, but does not work with Nvidia or AMD graphic drivers well. I would leave all of the early, early experimentation up to the bravest and check it out again in October!