I'm not sure there is so much one can do about preserving the battery health. However, while PC batteries are quite useless after 2-3 years, Apple batteries usually last 4-5 years - which is quite good. My MBP is now 5 years old, and its battery is pretty much dead. I'd say that the battery should last the entire lifetime of the computer, I mean I guess you would upgrade your computer anyway after 5 years of use? At least I do, hence I just replaced my MBP with the 13" Air.
However I must say I find the battery performance of my old MacBook White, 2009 model, last one before the white Unibody model - to be out of this world. This is not my computer however, we "rent it" free of charge from the school. I use this computer every single day in school, and has done so since almost three years ago. This computer has 605 charge cycles, while showing 97% battery health. A full charge still gives me approximately 4-5 hours of use (depending on how I use it). Is this the case with other Apple computers? My old MBP from 2007 did certainly not have this battery health, after three years and LESS use.
605 cycles, almost three years old and 97% health - quite amazing if you ask me.