Apple released the latest version of the Macintosh operating system, Snow Leopard (or more plainly, Mac OS X 10.6) at the end of August.  Many pioneering individuals have upgraded their Macintoshes to Snow Leopard, and new Macintoshes are shipping with Snow Leopard installed.  If you are thinking about upgrading from Tiger or Leopard to Snow Leopard, please consider the following in making your decision about whether and when to go ahead:

• Snow Leopard only works on Intel-based Macintoshes, so don't invest if you have a PowerPC-based Mac.
• Any new system introduces new bugs, even as it fixes old ones.  Some of the inevitable bugs in Snow Leopard were corrected in the 10.6.1 update, but waiting a couple of months to upgrade will result in a more stable and problem-free experience.  
• There have been some people unable to use the "UVM" wireless network with Snow Leopard. ETS is working to diagnose and resolve this issue.  
• Do your printers, scanners, and other peripherals work with Snow Leopard?  Some do not, but printer and scanner manufacturers may catch up and provide updated software in the next few months.  Older devices may never be fully compatible. There is a compatibility list at http://support.apple.com/kb/HT3669. 
• Do all of your software applications work in Snow Leopard?  It may take developers some time to release compatible versions, which may not be available without cost.  There may never be compatible versions of some applications.  Compatibility lists are available from several sources, including http://support.apple.com/kb/HT3258 and http://snowleopard.wikidot.com/.  If you have Power-PC applications, you will need to install Apple's Rosetta software.  
• New Macintoshes now come with Snow Leopard installed, but UVM departmental and personal system images are in early development, and have not yet been completed and tested.  Additional set-up and installation work on your part may be required for wireless networking and for applications you need to use.  
• If your computer was purchased since June 8, 2009, you can order Snow Leopard within 90 days of your purchase date for under $10, directly from Apple.  Consider getting the upgrade now, but waiting a while to install it.
• IT support personnel are experimenting with Snow Leopard (spare equipment permitting), so it will take some time for them to be fully up to speed.  Until that time, they sometimes won't be able to help you when something goes wrong or doesn't work as expected.  

If you would like to experiment with Snow Leopard, and learn about it along with the IT professional community, please share your experiences on the UVMOUSER listserv.  Numerous questions have already by posed and answered there, and more contributors are always welcome.  You may want to consider installing Snow Leopard in a separate partition or on an external hard drive, so that you can work with it but still go back to your current system, Leopard or Tiger, for your production work.