The microsoft pub the ARR to achieve load balance and failover,but it only run on the iis7.
So i think the feature can be add to iirf that we can make iis6 can work like a iis7 with ARR.
By the way the jk is a not bad exp to refer to.
In jk it use bl worker to make balance and failover.
I make the load balance and failover by a exterior script to modify the iirf.ini to achieve,but it sounds not a good idea.