I have little doubt Java 7 will introduce closures in one form or another, but which form exactly?
On one end of the spectrum, anonymous inner classes already take us part of the way today, but their clunkiness leaves much to be desired. On the other end, Neal Gafter et al proposed an ambitious, Ruby-like extension dubbed BGGA closures (short for Bracha, Gafter, Gosling, Ahe, the authors' last names).
You'll find the power to weight ratio along the spectrum between the current clunk and adopting the BGGA proposal non linear. In that vein, Josh Bloch, Doug Lea and I propose Concise Instance Creation Expressions (CICE).
Loosely speaking, simple syntax sugar for anonymous inner classes buys Java 90% of the power of BGGA closures while carrying only 10% of the weight. We think it's the "knee in curve" where we get the most bang for our buck.
As for that remaining 10%, while the other leading brand omits a class name and supports non local returns and limited custom control constructs, CICE closures strike a fine balance between brevity and explicitness and raise the already famous Java readability bar.
Without further ado, Concise Instance Creation Expressions: Closures without Complexity. Let us know what you think.