On the specific topic of browsers - what difference does it make what browser a child is taught how to use the web on? Transferable skills should be taught, not specific technologies.
On mobile computing - of course it isn't a fad - just the way it is being sold at the moment as some form of panacea for all our eduction and IT problems is. Tablets are great, in the right circumstances. So are laptops, desktops, PDAs and whatever else is out there. We shouldn't be buying into the compulsive behaviour of the average consumer though. I have a bunch of friends who are all non-IT people and of those who bought themselves tablets, because of the fancy adverts and current hype about them, and after a few months they simply don't use them as they have no need for them, instead having gone back to their laptops!
Schools are not there just to teach the latest fad - they're there to give a wide ranging grounding in key skills for children to progress onwards from. You don't *need* IT to teach any subject other than IT, so when you do use IT, you have to use it properly.