Removing the home button might suck
I have a couple reservations about removing the home button.
1. If a gesture is to replace the home button and multi-tasking bar, it better be simple. Users who have limited mobility, motor skill problems, or gloves on, won't be able to do this easily.
2. The home button let's me know which way is "down." Now, I know that in the Apple HIG documents, they don't want you to care about which was is "down." I suppose the orientation of the graphics on screen would be enough. But if the gesture is directional in nature-- such as swipe down, then developers need to start thinking that way. As it stands now, many apps are grumpy about even flipping. Though these tend to be games.
3. If anything, I would like a couple more buttons on the iphone. I find it baffling why they don't have a camera button, but two discreet volume buttons.
It's not to say that you can't solve these issues with gestures. You can. And it's also not to say you have to cater to all the newbies. People used to be baffled by a mouse, after all. People will start to associate these gestures as normal and intuitive over time. The swipe, for example, is now "obvious" to users of touchscreen devices.
I'll be interested to see how they solve this.