IMO, we need more control over the port number that Apache determines to be canonical beyond that which is provided by UseCanonicalName, simply because there are so many options and permutations which are possible and applicable for different environments.
To that end, instead of overloading UseCanonicalName (and breaking the API), I'm working on UseCanonicalPort. Before I spend lots of time on this, I need to get a feel for whether this is an itch others think need scratching and would vote for including in 2.0 (I'm working on 1.3, 2.0 and 2.1 patches)...