I love the laughably leading question above the comments section, "Do you agree with Jepson's take? Or will .NET take a bigger bite out of Java?"
How about option three - Jepson is wrong, in that .NET does not come close to parity with Java and MS loses market share to developers who are abandoning Visual Basic anyway and they decide to pick Java rather than C#.
You see, my take is that a development environment is far more than the sum of a handful of parts from a single vendor. A parity between Sun and Microsoft is not the same thing as a parity between Java and Microsoft.
Point #1: Microsoft has a long history of not-invented-here that prevents them from encouraging third party development environments the way Sun has. As long as Visual Studio is your cup of tea, you're grand, for any other tastes forget it. Ultimately, that prevents serious innovation in their development environment. The various Java IDEs could not be more different from one another and they are showing strong differentiation in areas like plugins/adaptability and refactoring. Any improvements that Microsoft shows will be quickly copied. They on the other hand will have a much harder time keeping up with all of IBM, Borland, Sun, etc. on their respective IDEs.
Point #2: The comparison in the article is between Visual Studio .NET and Sun ONE and the point is made that most of what is on one of the Sun discs could have simply been downloaded. This point should not be glossed over or dismissed. Because most Sun tools are readily available to all developers they can be used to build web applications on any scale. That includes personal and hobby websites.
An example of this would be the Very Quick Wiki (http://www.croninsolutions.com/veryquickwiki/wiki/jsp/). I intend to install one on my own personal website to work on a project and open it up to third party contributions. There's nothing magical about the code that would prevent someone from writing an ASP/.NET version of the JSP code, but what would they run it on? IIS on a personal workstation is just for testing purposes not deployment. So the overall effect is to discourage hobbyist use of the technology. Unless you have a business reason and a business budget for your project you should stay away from Microsoft's tools.
To say that Visual Studio .NET is better than a combination of Netbeans + Sun's SDK + some libraries _today_ is to miss the point that they are available to everyone and .NET simply won't be. And there is nothing preventing people from achieving parity between the freeware and open source material and what Microsoft has with VS .NET.
Point #3: Which brings us to open source. When I write an application or web application using Java I can call on a vast array of open source for bits and pieces. For example, at Freshmeat.net a quick review of the languages attached to different projects tells us that there are 1194 Java projects listed (a number exceeded only by Perl, C, and C++) whereas there are 6 C# projects. That's _six_, as in single digit...
ASP existed for years without my ever seeing an open source framework to aid in development of complex websites. I would have killed to have had one for some of the projects I did. Over in the Java camp I can pick from Struts, Cocoon, Turbine, etc. etc. etc.
Need more examples? Need to display RSS on your website, you can pull the code out of one of my applications. Need to render a complex graph on the fly for a daily display on a webpage, use Batik from Apache to render it using SVG. I could go on and on all day but it's pointless, Microsoft is fighting an army of ants and it is running out of bug spray.