If you go over to Macworld.com you'll find a section on PI: Advanced Wireless. It's just promoting a speaker series at Macworld on wireless networking. But if you scan through the article it references Aiport Extreme X2 & X4 several times. And with the iTV on the horizon it seems like tomorrow would be as good of a day to release a new Airport as ever.
Airport Extreme X2 and X4? [MacRumors]