Official in the sense that those who made the crack have debugged it and made a final release?
I remember the problem with this was that you had to literally hack you iPhone to get it running. Call me when they offer an "official" SiriusXM program in the iTunes application store.
EDIT:
Sorry I didn't realize the date on this original post. Oddly enough there has been this
new app buzz lately.
Does Sirius XM support it? Will it show up in the iTunes store as an official application? Looks good to me.