According to Lorenzo Fertitta at today's UFC Fan Expo Q&A session (via MMA Junkie):
"We're looking at I think sometime in late April. We'll be in Toronto."
"We definitely want to put on a big show. We're excited about Toronto. I think it's going to be a massive market for us."
"It looks like we're going to try and do the Rogers Centre, we want to break the record for attendance to MMA."
"We'll try to get about 40,000 to 50,000 people there."
The UFC is finally coming to my home town, I can't wait.