This had the smell of inevitability about it. Yes, a Russian hacker got 3D maps working on an iPhone 4. It's not complete and turn-by-turn directions aren't working yet, but it's a start.
I expect there are a lot of disappointed iPhone 4 users out there who are pretty upset that the maps app has so little functionality on their older phones. I could make a half-case for leaving the 3D flyovers off, but certainly turn-by-turn would have been nice to allow. Dozens of other apps have no trouble running on the iPhone 4 or even the 3G model.
So readers, are you understanding about this Apple decision, or mad as hell?