For those of you who are still interested in getting an Apple TV with a built-in hard disk, Amazon is offering it NEW for $149. That's a darn good deal considering that Apple was selling it for $229 immediately before they released the diskless version.
Why would you want to buy a 1st generation Apple TV for $149 instead of buying the 2nd generation for $99? The answer is in the built-in storage. The biggest difference between the 1st and 2nd gen models is that the 2nd gen model does not include storage (presumably, there's a small amount of storage, but you can't sync your music, pictures, or movies to it).
As I'm waiting to receive my latest Apple TVs, I don't have any plans to get rid of my 1st gen Apple TV as it's a great "on the go" device. We have all of our music (60GB), all the kids movies and shows (90GB), and some pictures (~10GB) sync'ed to it and can take it on the road without the need for an Internet connection or another device. The new Apple TVs will not be as useful on the go.