I just spoke with Apple, and they said the only changes to the AEBS is very slight changes to the casing, and gift wrapping options......
I generally find that the people you call on the phone aren't briefed about anything other then what is on the website. Apple's website doesn't list anything different about the New Airport Extreme. However if you go to the links I posted in regards to the FCC reports for both the previous and current model, you will see that there is indeed a change in regards to the radio performance.