I took my time clearing Normal difficulty, killing every mob, searching every cave and revealing every part of the map.
It took me about 30h to do so with a MF-Wizard, having around +40-60% MF all the time.
During which 92 rare and 2 legendary items dropped for me. I needed to create 2 mules to store them all :-)
Looking at the numbers, I got roughly 3 rares/hour or 1 rare/20min. This seems quite a lot in my eyes, but I haven't read much about rare drop rates anywhere, so this might be by design.
For the shiny orange stuff, I got 1 legendary/15 hours.
I do realize that a lot of variance comes into play, taking rare mobs, random caves, events and luck into consideration. But I'm interested to see how your numbers relate and how much variance there actually is.
I'll try to update my numbers, when I cleared the other difficulties with this char.
(Keep in mind that I only counted dropped items, crafted and bought yellows are not included.)