After some delay, Alexander Rhatushnyak was awarded 1500 euros (I believe, the website doesn't say) for his 3% improvement on enwik8 submitted on May 23. The prize was announced at http://prize.hutter1.net/
His submission is http://mattmahoney.net/dc/decmprs8.zip
(linked from http://mattmahoney.net/dc/text.html#1440 . The link on prize.hutter1.net is broken). It consists of an archive and a decompression program. There is no corresponding compressor. I can't say how it works, but he had been creating a series of improvements to the lpaq series (tuned on enwik8/9) prior to submission. The program extracts a dictionary file similar to the one used in paq8hp12.