At Berlin Buzzwords 2012, I will be presenting 'maxscore', an efficient algorithm first published in the IR domain in 1995 by H. Turtle & J. Flood, that I find deserves more attention among Lucene users (and developers).
I implemented a proof of concept and did some performance measurements with example queries and lucenebench, the package of Mike McCandless, resulting in very significant speedups.
This ticket is to get started the discussion on including the implementation into Lucene's codebase. Because the technique requires awareness about it from the Lucene user/developer, it seems best to become a contrib/module package so that it consciously can be chosen to be used.