WD Drive Help

I have no technical expertise to diagnose the problem with my WD My Book Essential Edition 2 TB (although formatted it only holds 1.8 TB) external HD with USB 2.0. It operated fine even after falling off my desk onto a carpeted floor (it wasn't powered on at the time).

Then it inevitably stopped working. While I was copying files onto it, the finder window stopped displaying the folders from the drive and I was unable to eject or unmount the drive from my desktop using DiskUtility. It remained powered up so I actually restarted my Mac to possibly reset the drive. Then the Mac indicated it wouldn't recognize the drive but the drive still remained on. In my desperation I pulled the USB cable connection from the drive to my Mac and it still didn't power down. Probably even more stupid of me I pulled the power cord which finally turned off the drive. I'm afraid to even plug the drive in again.

What is the best course of action? Is it just a matter of removing the drive from the enclosure and inserting it into a new one? Also, what's the best data recovery program for OSX and is it possible to gradually get the data off the corrupted drive? I only ask this because I have 1.1 TB of data on the drive and my Mac HD only holds 230 GB at capacity so I can transfer the data to another external HD.

This one is model no. WDH1U20000 2 TB drive which I got back in September of this year 2009 and I understand that a new version of the 2 TB just came out, making support for the one I have unlikely. What I can't find anywhere is the specs of the actual drive inside the enclosure, so if anyone can help there, thanks

I'm tired of constantly getting contradicting and bad advice on forums and Western Digital support has been no help at all. I don't mean to repeat another thread, as I have looked through the forum with similar posts to my problem, but not the specifics.