MSFT stock is already down sharply actually (7%) in after hours market. Analysts are slaughtering it.
But yes, the xbox 360 is a minor business for MS, they could stop it any day if they need money.
The problem they have is their core business doesn't work well anymore either.
- Windows Vista failed and people don't want to 'upgrade' to Windows 7 either... The PC market is in deep recession, it doesn't help.
- Office looses market share to Open Office (even my state owned company replaced Office by Open Office...)
- Zune is losing to Ipod
- Internet Explorer is killed by Firefox and Safari month after month.
- On the net, Google completely destroys MS.
All in all, MS looks more and more like a fallen giant. It's now clearly heading south.