It is no secret that I am not an Apple fanboy, but if your wife had an iPad, it would probably the easiest transition for her to go to an iPad 2, even if it isn't the greatest hardware machine, and one could argue that the Galaxy Tab interface is just as good. Different (IE: "not Apple") doesn't mean that it is bad. Heck, my wife uses an iPad 2 at work, but has an Android tablet at home that she loves. She actually prefers the Android tablet since she has an Android phone, so apps are the same.
Of course, with Android, you aren't stuck with the stupid Apple iStore or whatever. I hate how much Apple software is always running in the background on my computer just for the times that my kids happen to plug in their iPods.
But again, ease of transition for her would probably be the iPad 2.
