Got some numbers for you, Matt. Last quarter:
PS3: 22.8 million units of software shipped.
Wii: 40.4 million units of software shipped.
Microsoft does not release quarterly software shipment figures, but their analysis does explicitly state that last quarter (that is, Apr-Jun 08) saw more software shipments than the same time last year. In other words, it is practically impossible that the 360 sold less software last quarter than the PS3 did. It very likely sold considerably more.
Using those conservative estimates (PS3 = 360 software sales), we get a total of 45.6 million PS3/360 software units shipped, and 40.4 million Wii software units shipped. I wouldn't be surprised if the PS3/360 total were closer to 50 or 55 million, but even with my very conservative estimates, Ps3/360 is still shipping more software.