I dont i'm afraid - i'm going on personal experience and annecdotal evidence from pro and semi pro freinds - the logic is that a) there is more room for servos etc in a lens that there is in a body housing and b) that the sort of shake you get with a long lens is not the same as that expeinced with a macro ( the former tends to be physical lens movement due to bulk and weight , while the latter is the normal hand tremors but magnified) therefore the len based systems can be tailored to the specific problem while body based AS has to be jack of all , master of none.
I agree however with the stupidity of saying that until now hand held macro has been a pipe dream as i have only ever taken hand held macro shots and I'm using a canon 20D and tamron 90 with no IS or AS - basically its down to good stance, steady hands , and keeping the shutter speed up - likewise with steve (fourwings) dragonfly work - most of those are hand held with a 30D and sigma 150mm - again no IS/AS
by way of illustration of my point these were taken with the 90mm and 20D hand held
