It seems to me that soon someone will come out with a box that will allow you to access both Sirius and XM. Of course, you would end up paying accordingly just like cable tv. Actually, some company will probably come around that will become the central distribution service that will allow you to subscribe to both and other up and coming satelitte companies.
Besides not having the money for either of these options, from what I've seen and heard, at this point, I have no desire to own either as they both are very bland to me. In fact, in many cases, I'd never consider listening to most of their stations. I almost never listen to commercial radio either because it sucks so extremely bad so saying it's one or the other doesn't really apply to me.
Now, wireless internet radio is a whole other thing in my book. That is something that I wish so much that I could have away from my computer. There's tons of good stuff in that direction for me. For now, it's just not in my budget. (Need a job that pays dollars instead of pennies.) Again, the future will probably offer some kind of device that will allow us to link up to everything from the various satellite stations, free commercial crap, cable and free commercial tv and to the internet. The real issue is getting all of these companies to agree on some sort of a common ground. It's definitely doable and would be a very desirable product to the consumer. Wouldn't be surprised at all if Comcast isn't already trying to work this one out.