No, but it does take a remarkably powerful system to stream at true 1080p with a decent framerate. Most streams you see will be using a program called Xsplit, which encodes realtime in h264 at whatever resolution you like. These streams often look slightly blurry because they are being played on a 1920x1080 monitor, but resized down to 1280x720 before being streamed because it significantly lessens the CPU power and bandwidth needed to stream.
Guys like Destiny on JTV broadcast SC2 in 1080p and the stream probably runs at 3000 kB/s upstream or more. Most people's upstream bandwidth can't handle it. It also kills your game performance even on a quad core at 4.0GHz.
Oh I know. I'm not creating issues, I'm merely stating that ultimately it comes down to luck. So difficult to encode sarcasm into internet posts.