What's there for 3g
* Folders
* Threaded mail
* iTunes playlist creation / editing
* 5x digital zoom: just tap on the display near the capture button, but be warned, it doesn't paint a pretty picture
* iBooks: we were having issues with the earlier build, but it seems to be running fine after today's official download -- PDFs work, too.
* Photos: you can now sort by albums, events, faces, and places
* Game Center: the icon is present, but as of this writing we're unable to connect to the servers. (Update: a number of readers saying it didn't come with today's download. We nabbed ours as a gold build, which might explain the discrepancy despite still being considered "up to date" by iTunes.)
* Spell check has been updated
* Spotlight search: you can search the web and Wikipedia from the home screen search bar. That said, not all our queries -- "Engadget," for example -- weren't offering the option. [Thanks, jkane08]
What isn't
* Multitasking: this is the big one. Double-tapping the home button doesn't give you the handy menu, there's no fast app switching, and background use is missing in action.
* Screen lock: normally in the multitasking menu (which isn't available on 3G), it's nowhere to be found, even under Settings. Bummer.
* Home screen wallpaper: you'd think this simple addition would make the cut, but sadly no. The dock has been given a visual upgrade, though.
* Bluetooth Keyboard support: we haven't tried this ourselves, but an influx of reports from Twitter suggest this is also a no-go.