There is a new carrier called Canadian Metro Airlines operating Dash-8 equipment based in London, Ontario.
They're using a former CCAir Dash 8 (N841PH) which flew into London Airport this week.
Not sure on routes or how many aircraft they will operate.
Hopefully this YXU-based startup gets off the ground. YXU-YOW and YXU-YUL seems like obvious routes, given AC's crappy level of service, 1 nonstop per day on the former and zero nonstops on the latter.
But yeah, there's probably enough passengers who want to go to YOW and YUL without having go through YYZ! AC should've realized that London, ON is a large enough place for such nonstop service - its population is over 430,000.