A 50mhz increase on PS4 gpu would make it close to 2TFLOPs, but everyone already assumes a PS4 upgrade(pre/post launch) is less likely due to heat issues cause of the smaller size. I disagree with the notion that something smaller is likely to make more noise and run hotter. One just has to compare PS3 fat with slim models. The PS4 will be fine and we will see similar upgrades.
Noise isn't that important when playing a game, they just need to be careful about heat. And an overclock wouldn't affect noise levels during OS/media playback because the GPU would be pretty much idling anyway.
I do wonder about heat though. With the fine grained compute, isn't there the potential to really push the GPU? Like how furmark is used for stress testing but doesn't reflect real world gaming, it might actually be closer to how a heavily graphics+compute APU would be used?