It's not all about units shipped
I suspect the outcome of the Android and iOS 'battle' will be similar to the Mac and PC world.
Android is cheap and good enough for most people. The numbers of people buying the top end Android phones is similar to the new GFX card every 6 weeks hard core gamers to the PC world. Frankly small and insignificant (in more ways than one on the gamer side!).
While Android devices soak up the mass market; those willing to spend a bit more for a better overall experience will continue to go with the iPhone. As a platform, OSX only has about 8-10% of the OS market, but in terms of computer makers, is third only to HP and Dell (http://www.idc.com/about/viewpressrelease.jsp?containerId=prUS22531110). More importantly, of purchases over $1000, Apple apparently takes 90% of the revenue according to research in June 2009 (since which Apple have seen a surge in Mac demand, but anyway, the link is here: http://www.betanews.com/joewilcox/article/Apple-has-91-of-market-for-1000-PCs-says-NPD/1248313624).
So, relatively low market share, yet pretty big profits. I'll take that over raw shipment figures any day.
And the same thing can be seen in mobile here:
So, there's no doubt Android is doing well; but I don't think Apple are too worried just yet.