I just bought a 17-40mm and I am super excited about getting it! I can't wait. I also have a 28-105mm currently and thinking about options for upgrading/expanding. I found I really don't use a zoom lens too much which is why I sold my 70-200mm f/4 for a 17-40mm. For me, 17-40 is a great walk around lens. I'm thinking of just trying out the 17-40 and if I find out I like just keeping it on and not using my 28-105 I want to sell the 28-105. I love macro photography so was thinking about getting a 60mm EF-S macro. What other options can you guys think of?