I think cyccommute makes a good point.

Today I was biking along with another cyclist, and we came to a light with maybe 8 cars waiting. There was no room on the right, so I just slowed and waited but the other guy went lane-splitting. Watching, it seemed to me that any of the cagers could've opened a door (say to pull an errant seatbelt in, or the bottom of a dress or something) or reached out a window to stretch, or tossed a cigarette out, and the cyclist would've had a problem. And that's not even counting the motorists who change lanes really quickly with very little notice.

I'm not sure it's worth it. Too easy for something unpredictable to happen. My kids are waiting at home to see me, and I need a break from pedaling anyway. I think I'll wait or else creep by on the right if there's room and no one's moving.