Apple has released a couple of updates for Epson and Lexmark printers for OS X 10.6. Not much is mentioned about the drivers, and they are said to include the "latest printing and scanning software" for Snow Leopard. If you are having troubles with your Epson or Lexmark printer, this update may help.
The standalone updates are available through Software Update and also through the following support pages:
Lexmark Printer Drivers v2.2 (121MB)
Epson Printer Drivers v2.2 (546MB)
The updates require OS X versio 10.6.1 or later, so be sure you have updated your system before applying this update.