That's because the differences between this iteration and the last, while significant, aren't really enough to merit a new number.
Instead, Apple has taken what was already a very good device and refined it. The changes make for a better product, but they aren't revolutionary.
At first glance, the new iPad and its predecessor, the iPad 2, appear identical. They've got the same shape, the same physical design and the same-sized screen. The new iPad is slightly heavier and slightly thicker than the previous model, but not so much that you'd notice unless you were critically examining both at the same time.
It's only when you turn on the new device that you start to notice the changes.
The biggest difference is the screen. The new iPad's display offers four times the resolution as the one on the iPad 2. It also offers a wider range of colors than the previous version's.
That means it can display games, pictures and movies in much finer detail and in more varied colors than before. High-resolution photos, high-definition movies and apps that were designed with the display in mind look gorgeous.
But the difference is subtle, and easiest to notice when you have the two versions of the iPad side by side. High-resolution items look crisper on the new screen than they do on the old one.
Not everything looks better. Apps designed for the lower-resolution screen on the old iPad look less sharp on the new one. That situation should improve rapidly, though, as developers update their programs for the new screen.
The second big change with the new iPad is that you can buy versions that will connect to Verizon and AT&T's new high-speed LTE networks.
The iPad I'm testing connects to AT&T's network. I saw download speeds on it of more than 20 megabits per second and upload speeds of about 5 megabits per second. That kind of throughput is comparable to the speed I see on my landline connection from Comcast.
Considering that the older iPads typically offered a download speeds no faster than about 5 megabits per second on AT&T's 3G network and much slower on Verizon's, the new LTE connection feels blazingly fast. With that kind of speed, you should be able to download movies, apps and songs when you are on the road about as fast as you can when you are connected to your Wi-Fi router at home.
But you have to pay $130 extra for the versions of the iPad with the LTE antennas, and many consumers in the past have chosen to instead get the less expensive, Wi-Fi-only versions.
Even if you buy the LTE version, you may not benefit from the speed enhancement. LTE isn't yet available nationwide from either carrier. And while the LTE antennas will work in Canada, they won't work overseas.
The third big change in the new iPad is a much better rear-facing camera. Not only does it have more megapixels _ 5 versus less than 1 _ it does a much better job in low light situations. And Apple added an automatic image stabilization feature that helps prevent shaky videos. The new camera allows the new iPad to take pictures and video that are about as good as you can take on most cell phone cameras these days.
But Apple didn't upgrade the front-facing camera; it's the same low-resolution one as before, which makes for grainy pictures and video calls. And it didn't add a flash to the new back camera, which means you won't be able to take decent pictures at night.