1. If it ain't broke, don't fix it
The new iPad is almost the same footprint as the iPad 2. The battery life remains about the same, which is an astounding eight to nine hours of use (outside of intense graphic games). Apple realized they have a good thing. They didn't change what worked well.
2. You can't please everyone, but you sure can please a lot of people.
The new iPad has the retina display, which every pundit expected. There were a lot of items expected that didn't materialize, but Apple made up for that by giving more than expected in a lot of categories. The new software combined with the new graphics isn't considered a huge technological leap forward, but it still puts Apple far ahead of other competitors.
There are no user serviceable parts on the new iPad (just like previous versions). By all accounts, if it breaks you are not going to fix it on the kitchen table with a set of screwdrivers.
4. Don't toss out a successful product line.
You can still get the iPad 2 instead of the new iPad. This decision expands the choices for people across a broad economic spectrum. For a lot of people, those who don't need bleeding-edge tablet graphics, the version 2 is more than enough, and now at a pretty good price point.
5. Once your product line is established, quit using version numbers.
The iMac machines have all been called iMac for years. There are different model numbers, different speeds, different screen sizes and different internal configurations. Essentially, however, they remain the same excellent machine for the user. Don't bother telling me that I have version 42 of the machine. Let the technician figure that out. All I need is the family name.
Of course the PC world has been doing that for decades now. Glad Apple joined in.