Two ways to go
ATT has two offerings. You can get the bundled regular Dish service or you can get ATT Homezone. I have Homezone so I know more about it.
I think the regular Dish bundle is just like regular Dish except it is billed on your phone bill and you have different customer support. I don't know if you have access to the Dish, as a subscriber, web site or not. Dish has three sets of Music channels including Sirius. Sorry, Howard is not provided. HD program is 30hrs on the VIP622 and 50hrs on the VIP722. Some Dish boxes allow you to connect an External Hard Drive to allow more, lots more, DVR storage.
ATT Homezone is almost Dish with less and more. You get a custom ATT Homzone on screen User Interface. It works fine. You are able to connect the HZ receiver with your PC via an ATT 2 Wire DSL router. This allows you to push Photos and Music to the HZ box for playback on your TV. This works via a stand-alone clumsy program called Media Scout. My TV does photos better via a USB Thumb Drive. You can use your photos as a screensaver slide show but only in a mail-slotted SD 4:3 box. They will not go full-screen on a 16:9 HD TV. You can download Movielink rentals to the HZ box. Expensive with few HD offerrings. I guess, ATT doesn't want you using the bandwidth you are paying them for. Use NetFlix instead. You can listen to ATT Yahoo Launchcast Radio through the HZ box. Works well plus you have Launchcast Plus service for free on your PC. Note Dish already has tons of music. Your TV will display Caller ID if you have the service. You can schedule recordings on your HZ box via the web. Works but not well. Searching is hobbled. You must know the day the program is running and then manually find it on the guide to select it. The interface is slow and user-hostile. You do not get Dish Interactive, Channel 100. Homezone support is great although they can't fix what is broken by design. HD programming is arbitrarily choked at 20hrs. Maybe they want you pay for more Movielink programming. Using an External Storage device is NOT available because I guess ATT doesn't want you to. The box is wired to do it. HZ has no online account management or customer support. Everything is handled by phone.
My personal plan is to sit tight untill January. If Homezone doesn't cleanup their act I will switch to regular Dish or DirecTV. Before I would re-consider DirecTV, I was with them for ten years, they would have to actually add HD programming and revamp their receivers and software. Knowing what I know now and if I had to pick today, I would go regular Dish. I would also buy my own VIP 622 on eBay and swap in a 500gb Hard Drive and add some Internal Cooling and an External Hard Drive. From what I've read, the Dish VIP722 and the DirecTV HR20-100, HR20-700, and HR21 series are all troubled.