I have used the following article to add an additional crawled propert to SharePoint 2010 user profile search. http://www.sharepointsteve.com/2010/10/making-custom-user-profile-properties-searchable-in-sharepoint-2010/
The crawled property is called NickName. This is setup, configured and searchable!
If i search using the following criteria "Nickname:Jon" i successfully return my user record as i have the nickname Jon populated. However if i just search "Jon" i get no results returned.
I have looked at the configuration for the Search Service, User Profile and for the search webparts but am unable to get this working.