refrigerators. With things like the Firewire home networking that was being praised by several companies last year, when all of your home appliances are networked, They will become vulnerable. Think about it... They already have an oven that can chill too, so you come home to find that your roast has been cooking for 8 hour instead of 3 and at 500 instead of 350. Makes for a burnt disaster...

my 2 cents anyway...
edit...
^yes a car. I think it was a beamer with Bluetooth. You can hack in on the signal and modify settings of the system. Also, there was another car that was running a version of Windows that caused a glitch where the car wouldn't slow down or somthing like that...
Anything that has remote access can be hacked, cracked and infected with something. It's just not possible to protect things like that.