We're not sure if this is culturally situated in Japan or not (personally, I find the smell of smoked wasabi somewhat soothing), but it looks like fire extinguisher company Air Water Safety Service and Seems has just started a brand new market with aromatic fire alarms.
Our best guess says this is mainly geared towards the hearing impaired, since the smell released by the fire alarm is supposedly so potent that it fills an area of about 50 square feet in about 2 and a half minutes, we imagine it'd work for the non-hearing impaired just as well. Seeing that smell is one of man's strongest senses, it does make sense (and seems much more practical) than installing flashing red lights all around your house is well... on fire.
There's a short video of the Wasabi Fire Alarm in concept form over here, for those interested in seeing how far they've gone in the development process up until now.
Currently, the Wasabi Fire Alarm retails for a hefty $560. A bit out of range for most of us, but wider adoption may lead to a price drop later down the line.