Here are some more comparison screenshots:
https://picasaweb.google.com/100669398699184156438/June102012?authuser=0&feat=directlink
Here is a link to download the updated graphics:
http://www.dna-iq.com/Resources.zip
To install them on a Mac, open your Avernum - Escape from the Pit folder, right click on the app itself (called Avernum), then click Show Package Contents from the resulting drop-down menu. Then you should open the Contents folder, then backup the Resources folder to another place on your hard disk. After you've backed the folder up, put the contents of the zip file into the original Resources folder, and tell it to overwrite any existing files when you are prompted.
To install them on Windows, navigate to Program Files -> Spiderweb Software -> Avernum - Escape from the Pit -> Avernum Files. Then backup the folders called Avernum Graphics, Avernum Graphics Core, and Avernum Graphics PC to somewhere safe on your hard drive. Then simply copy the contents of the zip file into the three original folders, and overwrite the original files when prompted.
To get the original graphics back, then simply copy overwrite the original folders with your backups.
Note: this process will only change the graphics. Text files will not be overwritten, nor anything else that could affect gameplay.
I'd love to hear what you guys think of the new graphics.
In the exceedingly unlikely event you have any issues, describe the problem and I'll fix it right away.
Enjoy