"Standard" greenpower (desktop) :
http://www.wdc.com/en/products/products.asp?driveid=336
AV greenpower (embedded) :
http://www.wdc.com/en/products/Products.asp?DriveID=388
Then there's Blue (desktop) and Black (desktop) product lines. These drives all look identical (and have the same weight), I wouldn't be surprised if they have the same mechanicals and circuit boards with the only difference being some firmware tweaks and different warranty levels...
My supplier has these models with only a few bucks difference in price between GP and AV, has anyone used them? Just wondering whether they'd be better in a server, or whether it's just a pretty badge for a few extra lines of code to make the drive run a bit slower to reduce noise.