With hindsight, it's obvious why Apple stopped numbering their iPads.
In March Apple announced the "New iPad"... the one everyone (except Apple) calls the iPad 3.
This week they announced a 10 inch iPad with a lightning connector and improved processor/graphics. Everyone is calling this the iPad 4, except me: I call it the iPad 3s.
In fact, Apple are advertising this latest device as the "iPad with Retina Display". This is rather confusing because the iPad 3 also has a retina display.
However, there's no need to worry, because you can no longer buy an iPad with a retina display, 30pin dock connector, underpowered cpu etc... in other words: Apple have dropped the iPad 3.
It doesn't take an Apple Genius to see what happened.
Apple "had to" release an updated iPad in March. Let's be charitable and assume there were technical issues that meant it was under-powered. The point is, Apple knew in advance it was a stop-gap device.
The evidence? They didn't call it the iPad 3.
They didn't want to drop a device called "iPad 3" while they are still selling the iPad 2. So they called it something else.
I hope the millions of The New iPad (3) owners appreciate that. But don't feel bad - you got the limited edition iPad. And you could always buy the iPad 3s as well.
Nice work Apple.