As someone who technically lives in Rosedale (I say technically, as I'm in the steerage-class section of the neighbourhood about as far from the bluff as you can get), I agree that its probably not going to be a neighbourhood where you're going to see a ton of rowhouses and multiplexes, no matter what the zoning. The land value is probably just not going to make it very economical...unless prices go insane, there will most likely always be a more lucrative alternative for a developer to build on. This may not go over well on this site, but I actually would prefer it doesn't get inundated with development either...or if it does, atleast the quality remains high... there's a nice aesthetic character to this neighbourhood, and the last thing it needs is generic duplex boxes. I like that we have a variety of options in Calgary, and not every neighbourhood needs to turn into Bridgeland/Altadore.
Now having said that, what I do think would be interesting AND viable in this neighbourhood, is people building laneway houses. We are lucky to have some really nice alleys here, and most of the lots are fairly wide...so I think it's pretty ideally situated for laneways. With SAIT/ACAD nearby, they'd be perfect to rent out to students. It would be a nice way to add some density, without really disrupting the vibe of the neighbourhood. I imagine you'd also get a lot less neighbourhood pushback.