[Phanx]

Originally Posted by Tiok With "event" gone, how do we tell which event occurred in the XML-defined OnEvent handler? how do you get access to event arguments inside the XML-defined OnEvent handler, so you can pass them through?

As with self, the event and any arguments are passed to your OnEvent handler. These are identical:

local myFrame = CreateFrame("Frame", "MyFrame")
myFrame:SetScript("OnEvent", function(self, event, ...)
    -- self is a reference to the frame
    -- event is a string indicating which event is being handled
    -- ... is a vararg containing any and all arguments passed with the event
end)

<Frame name="MyFrame">
    <OnEvent>
        -- self is a reference to the frame
        -- event is a string indicating which event is being handled
        -- ... is a vararg containing any and all arguments passed with the event
    </OnEvent>
</Frame>

As someone else already pointed out, you get the individual arguments like this:

local arg1, arg2, arg3 = ...