This is clearly unacceptable, but T-Mobile does not have a solution as of now. Their customer support staff have been handed a list of points to discuss with the customer, including insane suggestions like staying away from low rated marketplace applications and turning 3G and wireless syncing off.
The final solution they suggested was to check out the local Circuit City to see if they happen to have any batteries that fit the phone because T-Mobile currently does not have any accessories in stock for the new phone.
The only remaining solution is to return the phone for a full refund, which I’m sure a lot of people will end up having to do.
When I confronted the support rep with the battery life times posted on T-Mobile.com, he blamed HTC. Great way to take responsibility for a problem.