The battery life of the cellphones is a big concern. Of course, it's a great excuse to cut an unwanted call by saying "My battery is dying.", but there are more disadvantages than the advantages here. It's like Murphy's law - When you really need to call up somebody, you end up having low battery.
I am fed up with number of chargers lying around in my house. Every time you buy a new phone, you get a new charger. No cellphone manufacturers like to have their two phone with same charger style. They take pride in re-designing the chargers... new shape, new connectors, new voltage, new current blah blah. So if you have n cellphones, you get to have n chargers. So when you are traveling, you need to carry all your chargers wherever you go (since charging stations are not really reliable yet). I wish all the cellphone manufacturers could come up with something like an universal charger, which can charge all the cellphones.
Or better still, if there is some sort of auto powered battery... or something with a hand-crank to charge the battery manually. It will be awesome if they come up with a battery, which can get charged with sunlight, like those calculators. Or they can use voice to charge the battery.... more you talk, longer your phone will get charged.
LOL, it will work better for the service providers.