http://www.kvr-vst.com/forum/viewtopic.php?t=57669
I`ve just spotted the above discussion over in the KVR forum. All the development/ programming talk is over my head 
but the general idea posted seems to be a different method of oversampling with better results than Hermite interpolation alone.
The examples arguru posted seem quite impressive.
I don`t know if this is relevant to the renoise sample engine but thought it might be of interest to the devs here anyway?
Edit:fixed link