Is there a way to assign a keyboard shortcut Outlook 2011 to move email to a specified folder?
By default there isn't a shortcut to move an email to a specific folder. You can use SHIFT+⌘+M to choose the folder. 

However, you can create an Applescript and then map that to a shortcut through System Preferences > Keyboard. Here is a sample script that will move emails to a folder named Processed (here is the original source if you would like to learn more). 

You can save the file wherever you'd like, but the default Outlook scripts are saved in:

 ~/Documents/Microsoft User Data/Outlook Script Menu Items/


Note: as of Office 11 SP2, this location has been changed to: 

 ~/Library/Application\ Support/Microsoft/Office/Outlook\ Script\ Menu\ Items/


To create the shortcut, open up the Keyboard Shortcuts panel, and under Application Shortcuts hit +. It will give you a list of applications to choose from (Outlook 2011), and then for the menu title make sure you choose the name of the name of the script as it appears in the menu.