DS1 dropped the nap at 2.5, after 6-9 months of DESPERATE BATTLES and sleeping 5-6 hrs at night. He slept 10 hrs/night after I finally let him drop it.
DS2 is currently 14 mos, and takes a 1 hr nap and 10 hrs at night. So, I don't have a direct answer there, but he's on roughly the same course as the older one.
I actually do know some kids who kept napping till they turned three! I didn't realize that until recently, I was always wondering why people wanted to meet up so EARLY... oops.
But I think there's a pretty common second pattern where kids drop it right around 2. Not that I haven't heard even earlier, or everything in between
-Mich