It's not really "aimed" at anyone, it's a lot of different things at the same time - it's a test balloon and a safe guard against platform stagnation. That's why it runs on a desktop, an HTPC, etc. It also gives them an avenue to gain new customers who would otherwise not buy a desktop or gaming PC unless it was prebuilt. Typical prebuilts from companies like Alienware are ridiculously priced. They are building a GUI on top of Linux, not just giving them Linux. It's to provide a console experience for one market while retaining the power and customization that appeals to another. There are few downsides to this other than compatibility. For the user who is happy with their setup they can safely ignore this if they want or choose to experiment at some point. Most enthusiasts I know are open to trying new things and anxious to learn so I think they'll do fine with the curiosity factor from many in their traditional customer base.
This isn't just for the living room either and you can do whatever you want with it. I am actually pretty excited to have a Windows alternative for the gamer, particularly with the technology market shifting so drastically. The streaming feature is there to take care of compatibility concerns I assume.