I'm sorry that the article didn't go deeper, but it's just a first look at Visual J#. I pointed out that J# only supports JDK 1.1.4, and this should imply that J# is no replacement for Java 2.
As for whether it's ready for the enterprise, that's the question of the hour. Is .NET itself ready for the enterprise? I think the answer is yes, but lots of people disagree. We really won't know until the final version is released, and people start talking about their experiences building enterprise apps on .NET.
As for J# reducing Java to a language, I partially disagree. There are three key components to the Java platform: the JVM, the SDK, and the Java language. J# supports the language (albeit a mutated version of it) and an obsolete version of the SDK. And of course, it does not support the JVM. The net result is that J# itself is no replacement for Java 2.
But I think Microsoft's initial goal with J# is to support Visual J++ users, and nothing more than that. However, I think that Microsoft will take J# beyond that. Now that they have a clean-room implementation of Java 1.1.4 to start with, can Java 2 language and SDK compatibility be far off? There is nothing to stop them if they proceed in a clean-room fashion.