Western Digital Raptor is something as unique as a harddrive meant for the public masses with a rotation speed of 10 000 rpm. WD Raptor has since the introduction been the first choice for enthusiasts chasing optimal performance. The only drawbacks has been the lack of real storage space and fairly high prices. Topping the range for a long while has been the 74GB version, but now Western Digital has came up with storage space that in the context is fairly interesting. Since the new Raptor stuffs up to 150GB in it, but also the cache is doubled to 16MB. Raptor 150GB utilizes the SATA2 interface and costs around 2800SKR in Sweden (approx. 350USD). In other words, you still have to pay a whole lot to include a Raptor into your computer.
Source: IDG (Swedish)