I almost lost it when I heard the level of reaction.
To be honest, a device like a Game Boy can be used a a component in an explosive device, the casing, wiring, buttons, they are all things you could use to improvise something. Heck, people do it with cell phones.
I blame columbine-oriented stupidity and these "zero tolerance" and over-reactive policies. Kids have been doing even worse things or a very long time.
Now I'll say the bit that people will hate. To be honest 9/11 does mean people have to think differantly, and I think our tolerance policies in the US are all wrong. To be honest for most kids I think something like this could be laughed off, identifiable exceptions of course would be immigrant children from other countries, like those in The Middle East. The reason being that we know that such kids ARE trained to be terrorists as we've had a lot of stuff on the kids being trained that young. Children are also used as delivery systems for explosive devices, although in such cases they rarely are going to say "I have a bomb".
Bus Drivers and teachers generally speaking have a good idea about who is on their bus. If you have some kid that is from a region like The Middle East, Africa, or Central/South America or whose parents are first generation immigrants, then you might take something this with seriously simply going by the precedents with child soldiers and suicide bombers. Honestly I'm kind of surprised we haven't had a child-bombing by one of those groups in the US yet (if it was attempted, it was stopped covertly, and never mentioned to the media).
A lot of people won't like that point and the dual standard it represents, but I think it's far less ridiculous than calling a bomb squad for some kid saying "I have a bomb" when they could just be playing make believe, or something. A lot of people get enraged by such thing, but I do believe context matters. Among other things what the kid actually says what he plans to do with that bomb can be a factor, as well as anyone else he happens to be playing with and the nature of the game. If he's playing army or something and is on the "bad" team the kid saying "I have a bomb, I'm going to blow you all up" while the other kids are running around going "bang, bang, bang" then the people involved are idiots. The same basic logic applies when dealing with a school bus, and I notice there is very little in this article to explain WHY someone felt this reaction was appropriate, and I can only guess it was because of those stupid "zero tolerance" policies.
I think the local educational system needs to be handed the bill for the false alarm.