It is not the "new iPad" it's just the new "iPad". Next year will be another new iPad.
iPads and iPhones have actually been the exception to Apples naming practices. All other computers and devices have always kept their name year after year. If you needed to specify model you either use the year (computers) or generation (iPods).
iMac's have been iMacs since the first generation and through several radically different designs.
So most likely Apple will refer to this iPad as the iPad 2012, or the 3rd generation iPad; bringing it into line with their normal naming practices. The iPhone could easily follow suite with the next model. Who knows.
People will probably keep calling it the iPad 3 though. Habit is habit.
The iPhone and iPad are very unique products with some key differences between generations, thus IMO it is clearer if they kept the number sequence going forward. Perhaps as these devices continue to flood the market it will make sense down the road. However, one thing it does is it will eventually slow the changes in model years. Right now if a new iPhone, or iPad comes out that doesn't meet our expectations in advances, we are quick to criticize them. I believe that will change our expectations in the future with new releases being less of a huge deal. It is easy for a person to expect a huge improvement in a number change, vs just a year built change.