Two things can happen,
1. they are currently set to standard settings in the ecu and fitting new ones will be the same and it'll be honky dory
2. (most likely) the ecu has already been 'tuned' to the current sensors so the car will sit a abnormal heights because the resistance being reported is different..
There is a program freely available on tinterweb to allow you to login the eas box and reset the settings but as RRBlues says you have to set them properly, the easiest way is with a two post ramp (level of course) you pick the car up to the intended heights and right down the values for each corner, once you have got all the deatils for all the heights you then put these details back into the eas system, hey presto the eas will now attempt to get back to each of these figures (and hopefully stay there)..
I belive there is also a few units on ebay and such to allow you to talk to the eas unit..