The iPod wasn't another MP3 player. It was the MP3 player, featuring the most songs in the least amount of space. For mobile devices, this makes a big difference.

Compare the iPad launch video from today with the original iPod launch: http://www.youtube.com/watch?v=kN0SVBCJqLs

The iPhone was the first phone capable enough and attractive enough for third-party applications. It came two years ahead of competition.

The iPad comes after the Kindle, and alongside plans from Microsoft and others to launch their own tablets.