Update: Secure Flight
Initially, TSA has built some flexibility in to the system. TSA has stated that "small differences between the passenger's ID and the passenger's reservation information, such as the use of a middle initial instead of a full middle name or no middle name/initial at all, or prefixes and suffixes, should not cause a problem for the passenger in the near term." Nonetheless, customers need to provide the name as it appears on the document they plan to present to airport security.
Beginning Aug. 15, the name on the reservation should match the government-issued identification the passenger intends to present at the airport prior to boarding. Repeat travelers with current profiles need to compare his/her state ID with his/her passport. For most travelers, the names on these two documents will match.
If the traveler's name on his/her state ID does not match the name found on his/her passport, the traveler needs to align the two names so that they do match. This would require the traveler to obtain a new passport or state ID.