Adam, your article should've snuggle hugged Freshdesk!
http://www.google.com/enterprise/marketplace/viewListing?productListingId=9356+11308236248743392394 - 5 starred in the Google App marketplace.
Freshdesk is the only helpdesk to have as many integrations with the Google Apps platform (Google Contact sync, GMail gadgets, Google Analytics) + also integrates with three of the CRM systems you mention here (Nimble, Salesforce and Sugar CRM). You will also especially find the social customer management piece of Freshdesk interesting.
http://freshdesk.com/social-customer-service/