Regardless of the 'ordering', the Atom line of processors are designed for the <10W form factor. True, Atoms existed before the iPad, but they are in fact designed to compete in that power-range. The analogy works very well: the iPad 4th generation A6x processor is just slightly slower than the newest Clovertrail Atoms. The older Atoms (like the 330) probably are a bit slower than an iPad.
http://www.anandtech.com/show/6522/the-clover-trail-atom-z27...
So yes, perhaps I misspoke earlier. Nonetheless, I stand behind the analogy. Intel Atoms are Intel's version of the iPad A6x. They use roughly the same power and give roughly the same performance... but Atoms give you full x86 compatibility.
Perhaps a more appropriate way to say it... is that the Atom is designed to be a competitor to low-power ARM chips in general. Intel is making strides in making extremely slow, but power efficient chips. And in Performance/Watt, they're roughly on the same scale.