What if the home contained both normal per-regulations smoke detectors that alerted humans, and had other smoke detectors to alert your home automation system? We could call them sensors instead, to differentiate.
Ideally, the sensors for your home automation system would be configurable to your hearts content, their point is not to alert humans but to alert your home automation systems. The actual smoke detectors are for alerting humans, and are tightly regulated.
I see a future where the home contains many different types of sensors all over the house intended for data collection, and alarms for humans as well. Temperature sensors and heat sensitive cameras combined with smoke detection sensors would let you do some really interesting things with regards to detecting smoke, flame, or even overloaded extension cables.
One of the reasons I'm interested in my home itself being able to detect events such as fire or flood, is so that it could initiate an emergency offsite backup of any sensitive recently-modified files, and as soon as that completed or failed for whatever reason it can shred the encryption key used to boot the full disk encrypted partitions. It could also unlock doors, trigger a gas and or electrical mains cut-off switch, trigger camera feeds to record to offsite servers, call me or anyone else, or even draw attention to the home by turning on and off lights (or changing their color if you have the right bulbs).