Yes and no. Their built-in screen reader and other accessibility tools in OS X are great. The iPad has allowed me to read a book again-which I haven't been able to do in 2 years, unless I was sitting at my desk (can't see printed text). However, you can't, for instance, do some very simple things, like enlarge the text in iTunes, or change the size of the min/max/close buttons in the OS's UI.

Many people don't need/want full-screen magnification/zoom all the time, just the ability to enlarge some text and tiny UI components. For things like that, I find linux far more accessible.

All of that said, most of my accessibility problems with Apple center around OS X.

Though you also can't enlarge text in iTunes/app store on the iPod/iPhone, the iPad has a much more usable 3-finger zoom, as well as a screen reader. The iOS touch interface is, as a whole, very intuitive and easy to use.

It is a bit too sensitive in some instances, but also rather forgiving in others. I'm guessing that has more to do with the app itself than iOS or the touch screen technology.