I saw an online request for help (money) to put iPads into a school (It was via Stephen Colbert's twitter).
Tweeted back the question as to why it had to be iPads, if there are notably cheaper Android tablets out there ... got a reply that they come back with a reply, and then nothing.
So far I'm mostly curious as to why it has to be this specific brand, as opposed to 100 EUR off-brand Androids, and I've yet to see anyone answer that, beyond, "but...iPad!"
I'm not Stephen Colbert, therefore I'm not an authority on the matter, but here are a few reasons:
iPad is perceived to have higher quality educational apps because all the big players in educational software initially targeted the iPad (although, that part won't be true for much longer since the iPad marketshare is shrinking vs. all the other Android tablets).
Stephen Colbert has received free iPhones and free iPads. In fact, he has made a couple of satirical jokes on his show about not wanting to be blacklisted by Apple for all the goodies it gave him. These jokes probably didn't make him any friends at Apple, but I doubt they cut off his supply of free stuff because unlike the other journalists Apple blacklisted for badmouthing it, Stephen Colbert could retaliate so easily. That's what his entire persona is about.
The term iPad currently gets more eyeballs in the press (not to mention Apple has a bigger and more focused PR/branding budget, versus the fragmented PR/branding budgets that the manufacturers of Android tablets have). Also, many people still equate Android tablets with iPads.
The schools with the most newsworthy orders of iPads probably got them at a discount over and above the normal academic discount (or they got paid in other ways, perhaps the school administrators/teachers received free MacBooks, or Apple agreed to fund the school in other ways). The key for Apple is just to get the initial ball rolling. It doesn't matter if its first customers do not pay anything, or even if they have to pay them. The Return On Investments for generating news stories is generally worth it.