Who Knew - 2010 Postal Stamps 2-59 was released on:
USA: 22 October 2010
Food Stamps - 2010 was released on: USA: 2010
Murder by Proxy How America Went Postal - 2010 was released on: USA: 2010
Don't Be a Victim - 2010 'What If' Going Postal 1-4 was released on: USA: 20 August 2010
Primetime What Would You Do - 2009 Food Stamps was released on: USA: 9 December 2010
Release Me - 2010 was released on: USA: 11 November 2010
Yes. As of July 10, 2012, the US Postal Service is still selling them on their website. Ebay also has numerous listings.
Catch and Release - 2010 was released on: USA: 1 October 2010
Blind Dates - 2010 was released on: USA: 13 June 2010 (internet)
With In - 2010 was released on: USA: November 2010
I Fought for You - 2010 was released on: USA: 1 May 2010 (general release)
The Minimalist - 2010 was released on: USA: 2010
Hillers - 2010 was released on: USA: 2010