Music is the spice of some people's life. Not mine as much mind you, my iPod has less than 5GB of music and 27GB of video, but that is just my preference. I don't think I have bought a CD in about a year. But there are some people that do enjoy music and listen to it quite a bit.
A colleague of mine has a stand alone Sirius radio in his car. And he bought the home adaptor kit to be able to have music selection through his home stereo. But he also has an Apple TV with 80GB of music. Given that he can stream music to his stereo from either source, or his computer if he wants alternate stations, is there one that is less useful than the others.
The benefit of satellite radio is the easy of use and the number of choices. You pick a channel that has the type of music or talk radio that you want to hear, and it plays it. You may hear something completely new, but it is still within the framework of what you had desired. However, it does require either having a dedicated satellite radio box for the home or transporting it from the vehicle and back. As well, there is a monthly access fee, but you do get access to unique content that can not be found anywhere else.
Apple TV is another alternative. In this case music and video can be streamed to the stereo. The large display, as it is being viewed on a TV set, and familiar iTunes interface makes it very easy to find what you are looking for, and to purchase new content directly. As well, iTunes streams radio broadcasts so that you are not reliant on only the content that you own. However, some of the bit rates for the stations can leave you wanting.
Lastly, there is streaming music from a PC. This is similar to the Apple TV solution as you likely have your iTunes library on the PC. As well, you have a wealth of stations and broadcasts that you can not find anywhere else, even if it can sometimes be difficult to locate what you are trying to find.
There are countless other alternative available for streaming audio. My question to you is "Is there still a place for satellite radio"? And just to put it into perspective (outside the digital home space) alternatives are available to stream audio via other signals, such as through a cell phone, for audio applications (which is where satellite radio seems to have the most traction).