Yes, it seems like skynet, but there is a major difference. In this case, the system does not control the robot. The robot (or operator) decides which information to download, so the control remains with the seperate agents. Humanoid robots can be very usefull, as they can easily adapt to various terrains. And, being humanoid, they can learn how to do things in the same way that humans do them. On the other hand, other robots can also be very versatile, but in a limited range of enviorments. For example, take the robot in the picture. This robot is the care robot from Tech United for the Robocup. As you can see, it is essentially humanoid, exept for the moving mechanism. This robot is perfect for indoor usage on one floor, helping a person in need of care. However, it will never go with you to the supermarket or drug store in order to get stuff. As for the effect of the signals on the enviornment, this is actually subject of many research projects. However, it is too early to say anything about the long term effects because of the short time that electronic devices have been part of our everyday lives. Remember that household computers were something for hobbyists until well into the 80s and mobile phones became commonplace only after the start of the 21st century. Real wireless communication on all kinds of devices is also something from the last decade. BTW, I found the link, see my original comment.
I think that the reason why you hear less about nanobots is because nanobots are indeed still under heavy development, but also because the news is somehow less spectacular. It isn't the realisation of some scifi idea without the actual applications. People like to hear about improvements like "nanobots now deliver cancer medicine to the cancer cells". Not about "nanobots can now hit targets with greater precision". You need the latter for the first, but the latter is 'meh' while the first is 'WOW!'. I am no expert, but this is my guess.