Looking at that device, It seems to me just radiating potential. Give or take a year of updates, I think the
TV will fit most people's living room needs perfectly.
I don't know much about Nvidia, but I don't think they do many small, low power GPUs designed purely for streaming & HD, I think there may be some truth to the game rumours, maybe psp or higher quality.
The HDD looks easily replacable, but we don't know if the software supports a larger disk, not much point buying a 2TB disk and finding you can only use 40GB of it.