You are basically describing pc gaming.
Standardized game boxes have been done before, MSX, CD-I, 3DO.
You can get pc gaming in console form too, Alienware X-51
What all these have in common as opposed to exclusive hardware is cost of entry for the consumer.
Specialized mass produced hardware, sold initially at a loss, will always beat licensed hardware that needs to be sold at a profit. Look at the difference in prices between standalone blu-ray players and the ps3 when the ps3 came out. The ps3 was expensive, yet standalone blu-ray players were $800 or more at the time.
Convenience is another big factor. 1 integrated online store and no worries about compatibility issues.
I am curious to see what Valve is working on. A Steambox sounds good, but can it compete with consoles. The Alienware X-51 certainly didn't catch on.
