I liked this bit from the Ars Technica News coverage on Sun's rumored license plans for Java:
Sun's decision to make the license less restrictive is probably a response to the rapidly growing popularity of Mono, an open source implementation of Microsoft's .NET development platform. A variety of unique and compelling Linux desktop applications built with Mono have helped to popularize the use of .NET technology on Linux. The .NET runtime environment, known as the Common Language Infrastructure, is an official ISO standard, whereas Java is largely controlled by Sun through its own standards body, the Java Community Process. Java popularity is also threatened by the recent hype surrounding dynamic language web application development frameworks like Ruby on Rails and Django. Developers have found that web applications built with Ruby on Rails require less time and resources to develop and, in some cases, provide better performance than comparable web applications built with Java technologies like Spring and Hibernate.