Just read that the Lotus ride height system was passed by the FIA in 2010.
Surprised they didn't use it last season then.
I think purely the concept was passed in late 2010 in the first instance. They were then probably developing it in more substance and testing it out in various measures during 2011. I know it was only first officially seen on the car at the Abu Dhabi test, but it is almost certain that they have tested it prior to this and it has not been spotted. I would imagine it is fairly complex to get working correctly, similar to the blown diffuser. The problem with anything mechanical is that it is difficult to just "bolt it on" like you can with aerodynamic parts and therefore maybe they have stole a march on the other teams by having this ready for 2011. If they have perfected it then it may be difficult for other teams to do so during the season.
Another interesting point is that this system primarily makes use of braking and suspension. Susposidly Lotus are using a push-rod suspension to take advantage of this system, whereas almost all other teams, used pull-rod (copying Red Bull) in 2011. Ferrari were one of the few teams to stick with push-rod and got a bit of stick for it, but this could pay off if this system is easier to implement with push-rod. Autosport has reported that at least one of the major teams has also submitted plans to have a variation of this system on the car ready for 2012, and Andrew Benson of BBC has semi-confirmed this is Ferrari.
I'm no suspension expert, but imagine if all the pull-rod using teams cannot now fully utilise this system? I'm sure it's not easy to change from push-rod to pull-rod or vice-versa during a season, right?