Isn't it time we finally move past the folders analogy? How many folders have you put in your pocket lately? How long do we have to continue replicating the archaic paper office methodology on our electronic devices? Forever?
How many of us have folders for our applications on our Macs? I sure don't. Everything goes right into the /Applications folder.
That said, I sure wouldn't mind something other than the 11 pages of random applications on my iPhone. I tried the folders hack for my iPhone, but I'm not great at organizing my stuff, so didn't bother reinstalling it the last time I upgraded the OS. I may have to install it just because I'm pretty much out of room on the Springboard unless I want to start deleting stuff to add others (I'm an app junkie).
I think the difference is that on the Mac there's a much more room to work with on the screen, and an easier interface than finger sliding.
On the other hand, with the Spotlight search on the iPhone, it's really pretty easy to find any application you want with just a few keyboard strokes as long as you know the apps name.