The Solid State Drive technology has already caught up to and surpassed the mechanical drives in terms of performance. SSDs are selling fairly well today, but it is being held back by the prices. Even if the prices are starting to get more humane they are still much much higher than those of mechanical drives, especially considering gigabyte/dollar. According to SSD and harddrive manufacturer Samsung this will change in just a few years.
The price of NAND Flash memory has dropped by 40-60% per year for he last five years and if this price development continues the storage technologies may be on par sooner than what most have been hoping for.
In 2009 the prices will be, just like many other markets, uncertain but by the end of the year the most affordable SSDs will be available with 256GB storage, unlike the 128GB drives of today. A small (?) step in the right direction at least.