Very similar format to before (will redo readme if people really want us to), but all account ids are anonymised, meaning that field on account is a) pretty dull reading b) now a bigint to support the placeholder value Valve are using. Total size of data compressed is ~15gb, full database is probably around ~70gb (if someone can post exact numbers below I'll update!).
We should have found and filled in the "quirky" games (matches with no matchplayers), although we're still lacking on some (most) of the skill data - we'll hopefully have come up with a decent way to share large data by the time we can fill these in.
For now though an apology for taking so long; large chunks of data are a massive pain, so we've given up trying to package it all up neatly into managable chunks because not doing so means we can release it now. People who only need a portion of it are probably better off to use the new API features to get exactly what they're after, this dump is aimed far more at people who'd like a complete copy of the data.
We do still intend to work out a way to get access to en masse recent data available, but for now the recent API changes make this considerably less of an issue than it was a few weeks ago.