Read this Wired article, "No encryption for e-passports" (by Ryan Singel). Not only will we have passports with RFID tags (which in theory can speed up and make more secure the exit and entry process), but they will NOT be encrypted.
Isn't this the kind of vulnerability that makes RFID so scary?
And perhaps even more scary - I have not heard a lot of mainstream press about this. This is most likely going to sail through and be implemented in the very very near future (Belgium is already doing it).
Be afraid, be very very afraid.