While I eagerly await my iPhone 4 to arrive this Thursday, I do get to whet my appetite with the new iOS 4 which was released earlier today on my existing 3GS. Weighing in at 378 MB total the update took about 25 minutes from download to update to the phone rebooting. Once the phone was back up I swiped in and was presented with my home screen with the background now the same as my wallpaper.  I made a quick visit to Settings to change out the home screen wallpaper to make things look a bit cleaner since my lock screen wallpaper was a photograph with a dark background. Not ideal for a home screen background.

Once that was taken care of I immediately updated my Pandora app to the new version that supported multitasking. I started a play list and double tapped the home button to go to my new unified mailbox and was pleasantly satisfied that Pandora continued to play in the background. Very cool.

While navigating around I did notice that the flow and transitions were noticeably smoother, fluid and generally more responsive.

The new digital zoom on the camera is rather gimicky since it is a digital zoom and only magnifies the view making for a rather blurry shot. Nice to have I guess though.

Folders are very nice though limited to 12 apps per folder. Not a big deal for the most part but I’m sure I’ll find this annoying down the road. Creating a folder is as simple as holding down the home button till your icons jiggle and then simply dragging one app icon on top of another applications icon that you want to group together.

Multitasking is very nice. The ability to switch between applications opens up a whole slew of new ways to interact with the device and applications. Double tapping on the home button allows you to see all the running apps, switch between them and close apps you don’t want running in the background any longer.

So far my early impression is very favorable. Lot’s of great new features and noticeably faster. I look forward to trying out Faces and Places with my photos and creating new playlists with my music.

This should keep me busy till this Thursday… stay tuned for my iPhone 4 review later this week!