I had the misfortune of getting to experience the new blankets on my IAH-EWR flight yesterday morning. I was excited when the FA mentioned that she had the new ones as I was looking forward to trying them out. Turns out that they are pretty darn bad. Super thin, they require doubling over to provide any sense of warmth. And the blanket is so small (~24"x48") that it is really only good for half a body anyways before being doubled over to actually prove useful as a provider of warmth.
Read a bit more about the new United blankets and see more pictures here.