GameCyte has a full interview with project lead Maciej Szczesnik who talks about the changes they've made. They caught a lot of flak over the poor translation of the game from the original Polish into English, and now they've re-recorded over 5,000 lines of dialogue along with all of the other upgrades and fixes. You can hear the difference between the old audio and the new audio pretty clearly by clicking on those links, but frankly... they just sound like different readings/voices to us. How does the plot change by hearing someone shout "Quick! To the laboratory!" any differently?
The new edition, which comes out September 16th, includes two audio CDs, a making-of DVD, an official game guide, a short story from the author of the book that the game is based on, and a map, and it retails for $49.99. However, if you're previously purchased the game, it's a free download. Hey, we're all for free stuff.