Um... actually I think one of the big selling points of the 27" is the input ability on it...
show me a blu-ray, dvd, xbox, ps3, wii, etc... that uses mini display port. fact is, until the magical adapter is available, the imac is simply not an input device.
as it stands right now, the only devices that can input to the imac are mac products... so essentially right now the imac can only be used as a computer display (and not even pc).