I think they both have their uses. Bird's eye instantly gives me a good idea of the general layout of an area I haven't been to before which allows me to sort of know where I am even if I take a wrong turn or the directions were wrong for some reason. But like Dr. Herbie says, Street View instantly lets me see what the building I need to be at looks like or know in advance when a certain turn comes up.
Also, I think this is the first Google video I've ever seen that features a) a woman and b) a guy who is not a t-shirt wearing twentysomething to get across that we're all young regular Joes having fun here at Google. Although it's not a product announcement video so maybe it doesn't count.