I really, really wish that CAN had caught on more for sensor networks in the hobbyist community.

It's so much nicer than I2C in so many regards: much longer range, masterless (any node can talk directly to any other node), packet prioritization built-in, deliberately designed to be more or less impossible to wedge, possible to do IC-to-IC on a board without transceivers by using a shared open-drain bus (like I2C, but with only one wire!)... and plenty more.

Really the only downside to CAN is that the spec requires timing that's tight enough that everything has to have a crystal on board. Ah, to have an alternate reality where CAN's timing requirements were relaxed enough for that not to be a requirement and it had caught on as the IC-to-IC interconnect standard instead of I2C...