The British RFID passports have had their encryption broken already
New RFID passports are supposed to make identity theft more difficult and to make it easier to spot fake passports like the ones used by the perpetrators of the 9/11 attacks.
First, making the data remotely secretly readable without every possessing or otherwise coming into contact with the passport hardly makes it more secure against identity theft. Second, it's hard to make fake documents, but easy to fake 1's and 0's. Last I checked your electrons look just like mine.
Besides the very obvious flaws in this idea, all it would take for the "secure passports" to turn into a nightmare of unprecedented proportions would be for the encryption to be broken. Oops, it's been done… and in under 48 hours of effort.
In the article, they mostly talk about the dangers of cloning passports, but I submit that the real danger is being easily, quickly, and remotely identified as a foreigner while you travel. Either way, they said it best in their final paragraph:
It may be that at some point in the future the government will accept that putting RFID chips in to passports is ill-conceived and unnecessary. Until then, the only people likely to embrace this kind of technology are those with mischief in mind.