My take would be that children change so much and so quickly that they're very hard to lock into a device or a platform. The things they cared about last week they don't care about next week which means that their old apps are largely irrelevant to them, and their brains are so adaptable the learning curve on a new device is no barrier at all.
The kids down the road from me have iPod Touches, the ones with phones have a BlackBerry and an HTC Android phone respectively, they share the family iPad and both have or use Windows 7 PCs. They move between these without a second thought depending on what they're doing, what's nearest, their mood or who the hell knows what other reason.
Let children choose what they want to be interested in and encourage it without pushing any prejudices you may have on them. This is technology - how much of what we thought was a big deal 10 years ago remotely matters today? Anyone still fretting about Microsoft's monopolistic attempts to take over the internet?