Markham council rejected the idea of a casino in the summer, so I'm not sure how this will get approved. There would have to be some benefit to the community beyond simply adding jobs. I have a sneaking suspicion that this will be proposed as a way for the city to pay for its part of the arena.
Personally, I don't have a problem with a casino in Markham Centre or another suitable site, but I think I'm in the minority. There is certainly a demand in the area though -- a friend lives in Markham Centre and there are (reportedly) a number of "gaming houses" in his building.
http://www.yorkregion.com/news/article/1383681--markham-won-t-gamble-on-casino
