Is a mSATA-based SSD something that you have to have, like a 2.5" SSD was on the desktop when Intel launched its X25-M? That depends on your application. Many decent Arrandale-based Core i5 notebooks cost in the neighborhood of $600-$800. Tacking another $100 to $200 is a hard sell, especially if you're not running the enthusiast-oriented workloads that make an SSD so attractive for your workstation at home.
On the other hand, we've seen how the performance of an SSD helps contribute to efficiency, too, making the SSD 310 a potential battery-saver. At the same time, the device was also created to address environments where the 2.5" form factor simply is not viable. In those applications, an mSATA-based SSD could prove key to enabling plentiful storage at a reasonable performance level.