It must have been a nice surprise to see the Jazz 146, when you didn't even know about them! The 146 is my favourite "Air Canada" type, and I'd like to see more of them. I'll have to get to YUL one day soon and catch one of the LGA departures/arrivals. I freaked out last year when AC said they were going to park the 146's; I'm glad they somehow changed their mind. They're the closest thing to 'variety' we have up here.
I believe AC has 8 146's in total, 6 from Air Nova, and 2 from Air BC(I'm sure someone will correct me!), both of which are now part of 'Jazz', which is AC's new name for their regional branch, as mentioned above.
Next flight.... who knows.