If this did happen, I don't know what anyone would subscribe to SiriusXM's internet package. The only thing their online version has going for it is original content and non-music content.
Actually, I've thought about resubscribing to satellite radio, but, if I do, it will be the internet package only. Here's why: (1) I have a good data plan with my iPhone. (2) It's about a dollar a month cheaper than having a satellite radio. (3) There are plans in the works to let users personalize the individual stations on the internet package. (4) I work in an office with no windows, which makes satellite radio listening at work useless.
I actually was interested in the Sky Dock because I heard you could get it for $10 with a one-year subscription. However, reviews in the iTunes Store indicate the app hasn't worked since an update to the iOS, and several users have commented that channel updates were never fixed on the Sky Dock iPhone app. So, that, too, helped push me more toward an internet subscription.
I have Slacker and enjoy it, but I wouldn't mind some extra variety, especially for at work listening, if it's quality programming. However, if I do end up going with an internet only subscription, I'll probably wait until the new customization features roll out. That way, I can see what other people are doing with it and how they like it.