Machinarium will be released on the 16th so it has already gone gold.
On October 7th from an interview with JD (
http://www.pixelsocks.com/2009/10/07/interview-with-jakub-dvorsky-of-machinarium/), this line is quoted (below) stating that the game was still being worked on as far as choosing which puzzles were right to leave in or how to make them more understandable.
We're not quite done with the game yet, because we've realized from watching players at PAX that some parts are too hard or not clear enough. However, it will be available on our website in the middle of October, and everyone who buys it directly from us will get the soundtrack as an archive of mp3s. It will also be available on Steam, Direct2Drive, and GamersGate.
**Moderator Note: I had to type the text in manually because mccartercar ran into the recent "disappearing text" bug*** (it tends to happen when one copy/pastes from formatted text, like the pixelsocks interview with JD)