Apple has released a couple of new printer driver updates for Brother and Samsung printers and scanners. The updates are for OS X 10.6, and include support for the latest printers and scanners from these companies.
These updates should be available in Software Update, but also can be downloaded from Apple's website via the following links:
Brother Printer Drivers for Mac OS X v10.6 (100.02MB)
If you are unsure whether or not Apple's drivers support your printer, you can check the following web page for the full list of supported devices: http://support.apple.com/kb/HT3669
In the past a few people have had problems with printer driver updates, so as with any update, do allow for others to test them first. Unfortunately it is impossible to test all of the drivers to ensure they work properly. Therefore, if you are inclined to apply this update take caution and back up your system with Time Machine or a cloning utility so you can easily restore in the event of a problem.