There have been a couple of bulletins released by the USPS related to IRCs. In mid-August, USPS advised post offices to stop selling the IRCs that expire in December 2006 as of1 September 2006 (some post offices are, apparently, are still selling them).
Last week, there was another bulletin that modified the USPS International Mail Manual to allow non-USA pre-2002 IRCs to be exchanged for stamps through the end of 2006. I posted the location of the latest bulletin, related to exchanging the non-USA pre-2002 IRCs, and now I have made smaller PDF files with both of these bulletins.Subject to bandwidth limitations on my free Geocities webspace, you may download these PDFs from: www.geocities.com/va7ewk/usps/
(Source: Patrick WD9EWK/VA7EWK/www.wd9ewk.net/DX-QSL via L Van Horn)