There is a 4/2012 version of the CHARM booklet. http://files.consumerfinance.gov/f/201204_CFPB_ARMs-brochure.pdf
There was no explanation as to what changed from the 3/2012 version. This is for both the CHARM booklet and the HELOC booklet.
I would say that if you previously linked to the FRB web site version of these booklets, you should update your links to those using the CFPB URL address. I think you can hold off on ordering new hard copies until your supply is exhausted but I haven't seen that definitively stated by either the CFPB or the FRB.