Indeed, AT&T announced EDGE before Cingular did. The problem is that EDGE is not yet sufficiently launched for GSM phones. From my understanding of EDGE- AT&T first launched EDGE for their TDMA phones.
Before getting excited, or annoyed, regarding EDGE would it not be better to wait until EDGE is fully launched on all GSM systems? Until then folks who want EDGE will just keep getting annoyed about their phone performances.