You need a whole stack of accessories to make it "work", but it's still very cool. For about $60 you can get up and running.
It depends on your use case, I think the relevant comparison point (as a value proposition) is the existing Pis. It's definitely true that if you're just trying to setup a network streamer, a conventional Pi 2 would probably be close to the same cost or cheaper at the end of the day, especially if you use a wired network connection.
Even in the wi-fi scenario it's probably close to break-even on the price, because the Pi zero a) only has one usb port and b) has no integrated networking or onboard audio. So to do anything A/V related a USB hub would be mandatory, which pushes the price up closer to the Pi2. And if you were planning on using ethernet, the Pi zero would "cost" a USB hub and an ethernet adapter (neither of which you'd need with a Pi2) at which point you're almost certainly better off with the Pi2 as it's close to the same price or cheaper and is significantly more performant (the Zero is basically an overclocked B+).
But depending on what you have lying around the house, it might be a very good value indeed, and for very low space installations, I'm sure it could be neat.
