Hadn't seen this discussed here yet... but maybe there is another thread I just missed?

I connect fairly regularly through YYZ to/from the US, last flight was about 2 weeks ago. This morning I came home to YOW from LAX connecting through YYZ and when I came up to the escalator that heads down to the YYZ customs hall they were diverting all connecting passengers to the left.

Went in to a small room and they had 2 agents checking passports (no NEXUS machines, so a short lineup) and then you went down the escalators and got on a bus. The bus takes you over to the D gates where you go up an escalator and show up right beside the AC service desk, beside the escalator that goes up to the E / F gates from the D gates area (i.e. right in the middle of the D gates).

So no security check when arriving from the US connecting in to Canada. The OSS on my boarding pass actually got used for something.

Not sure if this is a pilot or permanent but not having to re-clear security was very nice. Made an earlier flight back to YOW. If they found the space for a few NEXUS machines in there then it would be even better.