AT&T Ripoff As You Go? :)

The language is not isolated. Language is just part of the broader picture. if you choose .NET, you usually also need Microsoft IDE, windows platform (with all logging, performance monitoring, etc...) which is an investment (in terms of finances AND knowledge). if you choose java, it usually comes with different IDEs, different servers, different ways of logging, performance monitoring and ways maintenance is done. I don't think you can become an expert for everything. Sure, learning new language is quite easy. But learning how to get the best from the language and platform you use takes time and experience. And specialisation has it's advantages too if done with brain. I'd say focus yourself in mid-term, don't lock-off yourself in long term.