There's the Raptor WD1500AD for servers and the Raptor WD1500AH for gamers. Both drives feature 150GB storage capacity, 16MB cache memory, Serial ATA 2 (300MB/s) and Native Command Queuing (NCQ) support, Dutch tweaking site Tweakers.net reported. Other features like the noise levels (32 dBA in idle mode and 36 dBA in seek mode) and the 4.5ms seek time are the same as the previous generation.
It's expected the Raptor WD1500 will be as fast as the current generation of 10,000 RPM SCSI and SAS hard disks, with sustained transfer rates (STR) of minimum 85MB/s.
The difference between the gaming and server version of the Raptor WD1500 is that the latter one features support for Time Limited Error Recovery (TLER). If you want to learn more about this feature that improves error coordination between hard drives and RAID controllers I suggest to check out this PDF file from WD.
A German e-shop is already selling the WD1500AD for a price of 319EUR (approx $379). That's twice as much as the Raptor WD740GD which features 74GB storage capacity. The price of the WD1500 for gamers isn't available yet, but I expect it to be slightly less.