Carlos Perez: Java Is a Language for the Masses. Fascinating. With Java, there's apparently been a conscious design decision to reduce language malleability. (And the same would apply to .NET: the namespace becomes a shared vocabulary). Quotes Willam Grosso saying

The single best measure of whether a programming language is worth using is: how well does it support communities. The social aspects of the language dominate the technological aspects of the language

Do download Grosso's presentation for some more arguments.

On some level I totally, completely agree: when I'm thinking about building a "platform" level of APIs (which isn't really part of my day job, but I kinda stray onto that territory sometimes). If you're building a platform, the only sensible thing is to build it for the greatest possible, longest lived, most approachable developer familiarity (above, say, performance). One of the reasons that Web Services APIs are a Good Thing.