Apple have recently announced the latest update to their OS X operating system, OS X Mountain Lion (version 10.8) and as with any new operating system releases we will some incompatibilities with printers and multifunction devices.
Most manufacturers will be bringing out updates for their machines so you should check your manufacturers support site for the latest drivers for your device.
Apple have provided a fairly comprehensive list of supported printers and multifunctions on their website, this article was last updated as of 23rd August 2012:
https://support.apple.com/kb/HT3669?viewlocale=en_US#apple
If you are considering a new printer or multifunction and want to check if it is supported by OS X 10.8 give us a call and we will confirm the support.