Not sure about those WD drives you have in mind, but I've been running RAID 0 for about 18 months w/two Maxtor 40GB drives and love it.
For gaming purposes, it's awesome. Game initially loads faster. Levels load faster. If you have a fast CPU (at least 1GHz) and at least 256mb of memory, RAID 0 can really help you out in the gaming area.
Yes, there is ZERO fault tolerance and if it crashes you are screwed (that's why they call it RAID
0 b/c that's what you're left with if it crashes!

) but I don't rely on my main rig for storage/archiving purposes. I burn things like maps/pics onto CDs and/or store them on other HDs for backup purposes.
Benchmarks like HDTACH and SANDRA show my two drive setup to be about 33% faster (higher transfer rates) than a single drive. In my opinion, Zero Rocks!