So the interesting news broke that their is finally a proposal for closures in Java. My immediate feeling? Well for one the verbosity of the syntax proposal concerns me deeply, it is one of those things that unless it was thought of from the start will always be a problem to retrofit back into the language. The implications here is that we have a less than ideal proposal for the syntax when you compare it to say, Groovy's or Ruby's equivalent.
Is it too late now? My feeling is yes, Java has been around for a decade now. It has jumped several iterations to Java 5 (with Java 6 coming shortly) and the APIs have progressed hugely. The implications of adding closures would be huge, you would have to go back and revisit ALL the Java APIs. I mean, if closures had been around since the beginning the collections API would be entirely different. As would other things like the way we deal with transactions and file I/O.
Don't get me wrong I think it is great that they are considering it, even if it is a decade too late, but it will take a long time for the real effects to be felt until the APIs are made closure-aware.