UPDATE: Our ace commenters point out this is something Google has been pushing for a while now, pre-2.1, although it may be slowly moving across the US and hasn't been getting tons of attention everywhere yet. As the effect is likely part of the image downloads, Google can probably push new images any time they like, and not have it bound to any specific point release, so that makes the kind of sense that does. Still, pretty awesome feature!
Eagle-eyed reader Gregory just sent this in and as Neo would surely say -- WHOA!
Looks like for San Francisco, which is pretty much home turf for both Google and Apple, the built in iPhone Maps App now boasts 3D buildings! The renderings are in Map mode (Satellite and Hybrid modes have photographic buildings, after all!) and are pretty dang spiffy if you ask us.
Now, while I can see them if I search for San Fran, when I search for my hometown of Montreal, I get no such love. How about you and your city? Got 3D?