Like the fellas above meantioned, it is a state-of-the-art steering.
A 100% electrical steering is due to legislative reasons not possible yet (at least in Europe), but it certainly will be at some point. All major manufacturers are developing various
drive-by-wire solutions, i.e. it won't take long (<5 years) until they are widely spreaded.
As far as I know, Mercedes-Benz and Nissan are bringing (or already have brought) electromechanical steering into serial production this year (2013).
The major advantage is obviously weight reduction (and thus CO2), not only due to reduced number of parts, but also lack of fluid and/or the increased use of
polymer (plastic) components.
I personally think it's a good option (even as a after-market solution), but would wait a few years until those steer-by-wire-systems a) are affordable and b) have the major quality-issues (due to new technology) solved.
Edit: who's interested in a bit more technical detail/comparison, have a look
here:
=> Electro-hydraulic systems
=> Electric systems