The advantages of Java is that it easily serves as a lingua franca - everyone can read a Java program and understand what is going on. User defined macros destroy that property. Every installation or project can (and will) define its own set of macros, that make their programs unreadable for everyone else. Programming languages are cultural artifacts, and their success (i.e., widespread adoption) is critically dependent on cultural factors as well as technical ones. .. Most Java developers are happy to have dedicated, narrowly focused solutions that are tailored to a specific problem. I am keenly aware of the drawbacks of such an approach, but I don't see it changing very quickly.
Does this mean lesser power in abstraction and dumbing down programmers in an attempt to get a wider audience for your language (aka Language For the Masses - LFM) ? Paul Graham, in one of his rants against OO, mentions about the pack-programming world of discipline-imposing languages being oriented to social packs.
Do you think we are going through a change in the Java Culture and that Sun has changed its position on LFM over the last couple of years ? And how much it has got to do with the Ruby (r)evolution ? We have had the whole slew of features in Java 5 and now we are talking about adding on closures in the language and tail calls and tuples in the VM ..