I summarized what I found on the bboard in
this thread
most of them I'd already fixed in my own customization; like Rob, the sec_sessions char->varchar fix was the only one I needed to apply when I upgraded.
however as Don noted either in that thread or elsewhere, if you're doing stuff with timestamp fields pre-7.2, change them to timestamp(0) in the dump when you upgrade. this will save you much type coercion down the road.