The new Western Digital AV drives are based on a 3.5" form factor, and WD says they provide higher reliability, cooler and quieter operation, and lower power consumption than other models. Each drive is rated for a mean time between failures of 1,000,000 hours—slightly less than the 1.2 million hour MTBF of the company's latest Caviar RE2 drives. The drives have WD's ramp load feature, which improves non-operational shock tolerance; a preemptive wear leveling feature designed to reduce uneven wear on the drive surface; IntelliSeek technology that eliminates "hasty movements of the actuator" that increase power consumption and noise levels; and last but not least, SilkStream technology, which supposedly allows the drives to record or play back as many as 12 high-definition video streams at once.
WD says the AV drives have capacities ranging from 80GB to 500GB, and that they are already available with either Serial ATA or IDE interfaces. According to this page, the drives also have 7,200RPM spindle speeds, either 2MB or 8MB of cache, and rated noise levels of 26-29dB.