I was on one of the Wifi equipped 319's this week. I happened to notice a Wifi logo as I was boarding, which was the only indication it had Wifi - the flight crew didn't mention anything about it and I didn't see any signage onboard. I was chatting with my seatmate towards the end of the flight (E75 tags and sitting in J, so presumably a seasoned traveler) and mentioned the Wifi and she was surprised when I'd mentioned it the wifi, as there was no mention or indication of it inside the aircraft.

A bit surprised the flight crew wasn't promoting it more, but it probably helped to keep the speed up, given that few people seemed to know about it. Not sure if I'd use it regularly, as sometimes I like being forced offline for a few hours, but nice to have the option.