to be brutally honest, I'd much prefer see them totally revamp the saddledome and not build a new building. I know I'm in the infinitely small minority, but the dome is (in my mind) iconic, and instantly recognisable. Show photos of consol energy centre, Rogers arena, MTS centre, etc., and its likely people get them confused/have no idea which one is which. But show them a photo of the dome, and bam, Calgary.
I'm not suggesting a new coat of paint, I mean a tear-down to the concrete, and fresh install. Perhaps you engineer a way to raise/reinforce the roof to allow more concerts, and while at it, widen the concourse. You properly cover the bare concrete with more pleasant décor, and re-do most of the seats.
The saddledome is a recognisable landmark. It serves its primary function, to provide a large event space/arena for sports/concerts, quite admirably. For simply going to your seat and watching the game, it is perfect. But since modern business culture revolves solely around maximizing profit, it will be considered woefully inadequate.
Just my 2 cents.