OEM, RETAIL, BULK
Folks, just a little clarification here on what these means.
OEM = Original manufacturer, lessor warranty, terms may be different, etc, but MOST IMPORTANTLY, the warranty is through the company distributing the OEM product, in this case dell. That means when/if the drive fails, the recourse is not thru WD, but through dell. WD will decline any warranty claims.
RETAIL = self explanatory - what you buy in the retail chain, bestbuy, circuit city, compusa, etc. retails kits are retail
BULK = now this is a bit confusing. The product is sold similarly as OEM, that is, you get just the product, no owners manuals usually, no screws, just the drive in an antistatic bag. However, the warranty is through the original manufacturer, WD. Unless marked as OEM, most items you get from places like newegg and other online vendors (at least the honest ones) are BULK items with full manfacturers warranties, even though they are BULK packaged.
I used to work for an online merchant while back, and we'd constantly get calls with customers asking how the product could have a full manufacturers warranty even though it was sold as OEM. Customer was misinformed, as nowhere did we state the the said product was oem (unless indeed it was oem, in which case it was clearly labeled as such, and *WE* would be the ones to honor the warranty).
Hope this clears up some confusion for some about the warranty. As others have stated, best to buy this with your amex or click city card which extends the available warranty by a year.