RMA yeah, you will lost the data. Chances are it tried to do a firmware upgrade and it failed at some point. Check with WD see if there is anything you can do.
You can try to recover the drive as well as the data using the guides, but it will void the warranty.
My .02 cents, always have backups. Some people hate me for pasting the following link all the time, but I want to make sure people fully understand the consept of it. Just read the backup section.
http://howto.cnet.com/8301-33088_39-57556308/digital-storage-basics-part-3-backup-vs-redundancy/
