CNN.com - Sources: Major terror attack possible this summer - May 26, 2004:

Although there is no specific target, time or date for the possible attack, the information is the culmination of intelligence that has been known and gathered over time -- and it is the assessment that is new, the sources said.

Given this administrations past with non-specific threats, it looks like they might not be able to protect us against this one, right? It seems that there isn't actually any new intelligence to spur this warning, just a desire to remind the public that they need to be afraid and that the Bush administration is doing a fantastic job of protecting us.