Totally saw a guy with an orange City Mini in the city on Sunday... in the South End neighborhood of Boston (a very cool/yuppie/dog friendly part of town) and the City Mini was reclined all the way and contained... a dog!! I think it was a sheltie mix and it looked old, and it was just lying down, chilling, sniffing the air and looking out the front and relaxing as its owner pushed the stroller along.
I knew you all would appreciate this I've seen dog strollers for over $100 so I guess a City Mini is not a bad idea for a furbaby parent!!