After many failures with WD drives, I just gave up on them. I now have multiple LaCie and G-Technology drives and have never had a problem with them. OWC also make good drives.
The actual physical drives inside the WD enclosures may be totally fine. I have found that most of the time the Enclosure Electronics is what fails on the WD external drive I've had. This is VERY COMMON, in my experience. So Like the other poster I have stopped buy WD externals and switched to Seagate. So far I haven't had any problems with the Seagate externals.
By the way I still use all of my WD drives. I just had to take them out of the WD enclosure and connect them with a IDE/SATA to USB adapter I have (actually I have 3 of those adapters. Best money I ever spent on computer hardware).