I was recently reading what I had written about Microsoft, Sun Microsystems, and Oracle in 2004 as part of a business plan. My outlook for Microsoft was simple: Painful days are ahead but Microsoft has what it takes to succeed. Sun, not so much. Oracle could go either way.
Seems I was right about Sun, not sure yet about Microsoft. I now think Oracle is in a better position than they used to be.
One of the major things I noted was that Microsoft, despite a major institutional aversion, has been slowly developing and expanding services businesses. They have continued to do this, for example now offering to host Linux VPS's via Azure. Their services offerings in 2003 were more anemic than they are today. They are on the right track to deal both with open source competition and long-extended upgrade cycles.
I don't think Microsoft is about to die. They may be cut down to size but I think their offerings are large and diverse enough that they are more likely to be pressured to evolve than disappear. Many businesses in fact do this, see IBM's transformation into one of the world's largest IT services firms in the world.