Look at the companies that can be thought of as true competitors of Microsoft -- companies that have caused Microsoft fits in the past. There aren't very many such companies, but ones that come to mind (in no particular order) are Netscape, Novell, Lotus, Adobe, Intuit, and IBM. This is not intended to be an exhaustive list, just some that came to mind; if your company also qualifies, well, I salute you. Some of these companies were in businesses where Microsoft had ambitions, like personal finance software and fonts. Some were at one time bigger than Microsoft, like Lotus and certainly IBM. Some created products that defined whole product classes like Netscape and Novell. And in every case, if we look to the time when that competitor was causing the greatest grief for Microsoft, it was when they were also paying no attention whatsoever to Microsoft.
His point - Sun is still too focused on MS - unlike the examples he gives. Read the whole thing.