My BMW is "Sirius" ready but I'm using an XM Direct from Blitzsafe that allows me to use the controls on my head unit as if there were a Sirius unit installed. Pretty neat. Since I got a $50 rebate for the XM tuner portion of the unit, I got in cheap.
As for programming, as long as I can get XM Comedy, XM Classics (because of their on-air personalities), and Cinemagic, I'll be happy with the merger.
I also want to provide the following links for your reading pleasure. Written by someone who does not think the merger is a good idea:
washingtonpost.com
Pearlstein: XM-Sirius Merger - washingtonpost.com