Microsoft had a three part plan going into the industry. I remember when they released the very first X-Box that Microsoft and later Peter Moore said Microsoft had a three point plan. The plan wasn't elaborated on all that much but my uncle who works for Microsoft said that their was intent to build three X-Box's. The plan was one to deal with Sony as a threat to Windows and Microsoft's PC industry.
So what is the 360 accomplishing? It's hitting the PS3 really hard in North America and Europe which used to be two of Sony's strongest markets. Its outselling the PS3 globaly by over 10-million units and regardless of operating losses Microsoft is gaining far more then they are loosing. As stated Sony took losses of 2+ Billion opposed to Microsoft's 130 Million.
The idea of the X-Box was never to gain profit. It was to make Sony loose profit. To damage Sony's user base. As my uncle put it Sony was calling the PS2 a computer and all hints pointed to a possible Sony OS and computer system. Microsoft feared Sony might turn the PlayStation brand into a PC brand.
So Microsoft used a pre-emptive strike to kill any chance of Sony building an OS and PC by crushing Sony's so called computer. As long as every X-Box is one less PS3 owner Microsoft is winning. THe goal is and always has been steal the market share from Sony!