320 Gb on a single platter

The war on data density is still going on in the HDD-market, everybody's trying to push as much data on a single platter as possible.
Western Digital has just released a 3.5" disk that stores 320 Gb on a single platter!
This has two consequences:
- First, cheaper drives: because less parts are used, producing these drives is cheaper, and they'll probably cost around $100.
- Second: drives with huge capacity, close to 1.3 Tb (using 4 platters and 8 heads).
The fact that they're starting with the first option, proves that the market prefers a better capacity/price ratio rather than pure storage capacity, and they're serving mostly OEM-resellers (who tend to offer cheaper drives instead of top-of-the-line products).
Another advantage of having less moving parts in a drive is its lower power usage, and consequently less heat inside the drive.