I went 10-22, 17-55, and 70-200/4L IS. 15-85 wasn't available back then.
If I was "upgrading" from a 15-85, I'd be wanting to bring the 70-200 with me all the time. Hence, something like the 70-200/4L IS vs. a heavier 70-200/2.8L IS.
Having a 15-85 could mean you leave the 70-200 home more often if you want to travel light.
So if I had a 15-85 at the beginning, I wouldn't sell it when buying a 17-55. I'd keep both of them, hence making this exercise not an upgrade situation.