yet another Google revenue stream on deck…
If Google finds positive user feedback and usage, I suspect they would have very good leverage in negotiations with cellular carriers to incorporate Google SMS into default menus of shipping cell phones. This would make money for the carriers, and I would guess Google could extract payment for co-marketing activity. Anything that increases SMS queries would look pretty good to the carrriers. Often times, SMS sends cost money while SMS receives are free.
If Google accepts payment for priority listing submission or priority order in the response SMS, then they have a revenue opportunity for local business information directory services to the mobile device market. That possible future is hinted at on the HowToUse page. This could bring the yellow-pages style revenue model to SMS — Google could incent carriers to provide Google SMS sends and receives for free by sharing listing services revenue with them, and increase two-way SMS usage all around.