We suspected this when Apple didn't mention tethering and AT&T told us after repeated prodding that all device features were up to the manufacturer—i.e., the tethering ball is in Apple's court—but iPhone Atlas says they've learned that there won't be any tethering for the iPhone 3G.
As we mention in our ultimate iPhone 3G FAQ, written by the esteemed author of How to Do Everything With Your iPhone, they didn't allow tethering with the first iPhone either (not that EDGE would've been a wild ride anyway). This just seems to make it more of a lock—at least without some hackage. If Apple winds up allowing tethering, AT&T will probably come up with a plan, or simply apply its standard smartphone tethering plan, but either way, we'll let you know if we hear different. [iPhone Atlas via TUAW]