Android - a far superior OS
Ahem cough.
It has its weaknesses too.
Two examples :
(1) The whole Android open source ecosystem thing. The software and hardware are separate elements, designed and implemented separately. So you don't get the tight, user-friendly, stable integration that you get on Apple iOS based devices. Using an Android device will be just like using a Windows device in terms of keeping up to date... you'll have to keep both Android OS and Device firmware up to date. Rather tedious I would say.
(2) Due to the above, there is an inconsistent user experience. Different locations for buttons, different icons. Different update mechanisms. Messy, very messy

, even more so for non computer literate users.
And I'm sure I could come up with more.
Sure Apple isn't perfect either, but the iPad is a great product, and together with the Apple iOS system make for a very intuitive and usable platform.
47% of the market (and according to last Saturday's FT, that will be over 50% by the start of next year
Yawn.
Rule number one of consumer gadgets. Ignore "market share" stats.
Due to the nature of the devices and their users, the statistics are very volatile and can literally change overnight. You also have to ask yourself where they get the numbers from because the manufacturers are not exactly going to release such data to journalists (or if they do, it's probably padded up a bit).
Trust me, Apple R&D will be keeping up to date with every move of Android and making adjustments to their product pipeline accordingly. They're not stupid.
It's not like businesses who buy stuff on 3/5 year lifecycle ... if Joe Bloggs sees his mates using a fancy new gadget and he's got enough balance on his credit card, he'll go out and buy one on a whim.
Take another consumer market for example, gaming. There's Microsoft,Nintendo and Sony. All doing perfectly well in their own rights, carving their own niche and route to market in a very busy, incredibly volatile marketplace. There's no such thing as "marketshare" and no such thing as a dominant product that "killed off" the other manufacturers.