ATI used digital tuners back in the days of the Radeon 8500DV, but switched to analog tuners from Philips for more recent All-in-Wonders. For the AIW X800 XT, ATI has returned to silicon-based digital tuners, which supposedly offer higher quality and quicker tuning. Since the image quality of analog tuners has been good enough for recent All-in-Wonders, it seems likely that ATI made the switch to digital because smaller silicon tuners consume less board real estate.
ATI All-in-Wonder X800 XT Review
I missed this one yesterday, but our friends at Tech Report have posted a review of the X800 XT All-in-Wonder card that offers a healthy does of gaming performance along with great video input and output capability.