The land the Rogers Centre sits on should be kept either for entertainment purposes (ie: stadium use) or park land, and nothing else. Often times when stadiums are demolished, the land is kept "in reserve" in a sense by transforming it into parkland which would easily allow for the next replacement stadium to be built.
New York has done this with Yankee Stadium, Detroit has done it with Comerica Park, St.Louis has done it with Busch Stadium, etc. I can give countless examples where cities and teams work to keep the land away from development because they know once that piece of prime real estate is gone, they'll never get it back.
In Toronto's case, this is one of 2 pieces of prime real estate we have left in the downtown core for stadium use. Sell that off for condo development and we'll be stuck seeing baseball at Downsview Park for the rest of our lives. We're lucky in a sense that the Rogers Centre sits under Federally owned lands and not provincial/municipal owned lands because if it were the latter cases, I could see the land being sold off when push comes to shove. Especially when you get bombastic leaders like the one we currently have over at Queen's Park