In the past I’ve provided a custom OUTLOOK.HOL file to add the UW Holidays to Outlook.
You can read http://blogs.uw.edu/barkills/2008/11/06/uw-holidays-in-exchange-2/ for the first post where I mentioned this mechanism.
I’ve just updated the Outlook.hol file noted in that post to include the 2012 & 2013 UW Holidays.
Note that this newly updated OUTLOOK.HOL file is based on the stock Outlook 2010 file with just the UW 2012 & 2013 dates added. You’ll be closing Outlook, replacing the stock file at C:\Program Files (x86)\Microsoft Office\Office14\1033 with this new copy (to be safe, make a copy of your stock file first), then via the File toolbar, Options, Calendar, Add Holidays…, Uncheck United States and Check UW Holidays 2012 and 2013.
Finally, I note that Outlook 2010 has an internet calendar subscription feature, where you can subscribe to a web-based calendar. I don’t know how well this feature works, or if there’s an iCal formatted calendar for the UW holidays that’s maintained somewhere already, but it’s something worth considering as a possible better solution here.