I have the EyeTV Hybrid and it works beautifully on my MacBook and does a phenomenal job picking up the over-the-air digital TV signals here in the Chicago suburbs.
I am using a new Winegard outdoor antenna-- it's being sold as "compatible for HDTV" because, as stated here earlier, you don't
have to buy a special antenna just for HD. It's just good to have one high and outside (I wish I could think of a baseball joke, but I'm a little tired now

.
I don't think you can set up the EyeTV's software to decode both analog and digital channels at the same time. When I set up the EyeTV software for the first time, it gave me a choice of the signal source-- I had to choose between options such as digital over-the-air, analog cable, etc.
If you want to switch back and forth between sources, I think you need to run through setup each time. I may be wrong about this, but I don't think the answer is as simple as switching cables.
That said, the unit is awesome!