The first problem ... apparently they aren't planing on adding capturing of non-final variables. This is a PITA since a lot of anonymous classes are using just that by boxing those vars in final arrays ... which is the kind of boilerplate I could do without, but I guess readability of code is not a priority (oh, the irony).
The second problem ... the proposal is not final, but from what I've seen the "Function type" has to deal with primitives, and they are going to do that through code-specialization ... and if that's the case, it would be yet another case where they are introducing exceptions in the language (like it's the case for arrays or for operator overloading). I'm not even going to mention the "special" syntax introduced for collections.
The third problem ... since we are talking about fork/join, it would be best to leave the constructing of the query to the designer of the framework, therefore returning the syntax tree of a closure (instead of the method refence) would be really useful. The proposal doesn't include such "futurist" notions though (LISP's quote is very cutting-edge after all).
The fourth problem ... it would be best to deprecate Java in favor of something else running on the JVM. But what chances would a language have that isn't totally different (in which case it would diverge from the type system, therefore slow or with interoperability problems) or that doesn't have feature-bloat to differentiate itself from Java (like Scala, which IMHO it's an abomination). The point being that adding features to Java makes life harder for everyone (including people using/developing other languages). Why not concentrate on advancing the JVM instead? Still no tail-calls, still no stack-allocated objects (with escape-analysis not delivering on its promise), and invoke-dynamic is one whole year away from being released.
And closures are a language feature that happened long before Java appeared, and it's been talked about it ever since the start. See this article about "Microsoft's delegates" ... http://java.sun.com/docs/white/delegates.html
Now they want to add closures because that's the only sane way to work with fork/join frameworks? No shit. It saddens me because it took a really loooooong time for them to realize this ... design by committee at its best.
