One million in 28 days indicates not only success for Apple, but for the tablet form factor as a whole. Expect now even more energy to getting other products in this form factor out the door. I think Christmas 2010 is going to be an interesting gadget holiday.
I keep thinking how this was inevitable. The original Palm Pilot was really the first mass market tablet. Sure it was small, and needed a stylus but those of us that had it, loved it. It could even surf the net in its own way. You could capture web pages on your PC and using the Avantgo application, download the pages into your Palm Pilot for reading while out and about.
The Palm Pilot begat stylus based phones like Palms own Treo and HP's iPaq and then touch panel phones like the iPhone and most recently Android based phones.
I was there when the Apple Mac came out in 1984 and spelled the deathnell for the command line user interface. Touch is a similar quake in the tech ecosystem.
We now have several tablets in our home: phones, an iPad, and an iPod Touch. And in time we'll have more. Perhaps an intermediate tablet like the Archos 7. And even larger screens like our televisions will have touch like abilities, finally ending our love/hate relationship with the remote control as the remote goes the way of the mouse.
Gesture recognition systems won't expect you to touch the screen to receive your gestures, but rather a video camera will watch your movements and have the screen respond. Microsoft's Project Natal, designed to allow gesture inputs to video games, could easily evolve into a system like I describe.