list of haste items
I suspect the 50% haste robe is a GM item of some sort and the majority of the 46% haste items appear to be from OoW/DoN raids. 45% haste items have become much more common on live servers. Group gear in the current expansion (Seeds of Destruction) starts at 37 then goes to 39, 41, 42 and tops off at the aforementioned 45%.
I'm not certain how v3 haste works on emu, but I do know that on live bard overhaste was capped at 25% (including lower level songs that were previously 30%).