Brant;

You and I seem to be on a similar path...alot of what you are considering has been running through my mind as well. I upgraded to the 5D3 and 24-105 last May from a 7d and 15-85 as well. Current lenses are similar as well: 50 1.4, 100 2.8 macro (not the L though) and 70-200 f/4 IS (w/ 1.4 tele).

I'm fairly happy with the mid-range of my kit so I'm looking to extend it at either end. Firstly I'm looking at something wider (I haven't had anything wider than 24 full-frame yet), currently debating between the 16-35 and 17-40. I also want to extend my reach at the other end...but really have no idea with what. I like the idea of the 100-400, but am also tempted by the super-teles (just not the price or lack of portability).

Another lens I'm often tempted by is the 135L. You mentioned you liked the 85mm focal length on the 7d so perhaps this would be something you could look at? Not sure how this would fit your intended usage though...a bit short for most wildlife and not necessarily ideal for a travel lens. I'm condidering it for the potential use in family portraits (particularly of my infant son).

I know this is not much help, but just wanted you to know that it seems I'm also in a similar situation and will be following this thread closely!

Stephen