I actually had Smackdown vs. RAW 2008 for the Wii pre-ordered up until this past Monday. I started reading reviews on Mario Galaxy and changed my pre-order from SD vs. RAW to Galaxy, and I haven't looked back since. I've heard awful things about the Wii version of SD vs. RAW, and I've heard nothing but great things about Galaxy. I definitely made the right choice, and I'm enjoying it every minute.
Along with GH3, I'll be playing Galaxy for a long while. Those two games made my Wii experience a great experience.