He's got ties to Pakistan:

NEW YORK — The search to find out who planted a car bomb that fizzled out in crowded Times Square took an international turn Monday as law enforcement officials said they were seeking a potential suspect who had recently traveled to Pakistan and had used cash to buy the SUV from a Connecticut man.
Authorities identified the buyer of the SUV used in the botched bombing after interviewing the registered owner of the vehicle. One of the officials told The Associated Press that the potential suspect is a man of Pakistani descent who recently traveled to Pakistan.
The officials spoke on condition of anonymity because the case is at a sensitive stage.

Officials had initially thought the job was likely domestic due to the amateurism, even though the Pakistani Taliban claimed reponsibility. This doesn't say much for authorities' opinion of domestic terrorists, nor their assessment skills. The shortcomings of the bomber are already well documented.

UPDATE: His name is Faisal Shahzad: "Faisal is a Connecticut resident and a naturalized citizen. He recently returned from several months in Pakistan."