I too have been interested in this. I have two Premieres, both with WD10EARS drives in them. One drive I expanded myself, and the other was a DVR-Dude drive from ebay. I have been feeling a bit cramped with all my HD recordings, so I have been thinking about upgrading to WD20EADS/WD20EARS or WD20EURS, but I wanted to expand the drive again if at all possible. I will be ordering the drive(s) next week and get back with results, but this is promising that someone else was able to do it.