The Eid stamp was part of a series of holiday commemorative stamps. In November 2001, it turned out that the stamp had been left off of promotional "Holiday Stamp" posters sent to post offices around the country. The Post Office claimed it was an oversight (and it probably was, given that the stamp only came out shortly before the posters were being readied for printing), but given the timing, people were a little suspicious.
Eid is an inoffensive holiday (unless you're a goat), and there seems to be an effort by American Muslims to turn Eid into a Muslim Christmas (as Hanukkah has practically become for American Jews).
I am far more offended by this:
http://www.usps.com/communications/n...4/sr04_070.htm