Buildersmate always gives very sound advice and if I was doing my bathroom I would definitely follow the links he provides.
Having said that, about six years ago I did our bathroom, using the dot and dab method for plasterboard and installed a shower unit at the same time. Incredibly, I didn't even think about any special preparation for the shower. (Incredible because I usually follow all recommended codes of practice and regulations etc) it just didn't occur to me at the time.
I used tile cement which was recommended for wet locations and separate grout which was similarly recommended (I don't use the combined grout and tile stuff, I just don't like it).
It wasn't until a couple of weeks later when I was next in a builders' merchants that I even thought about aquapanel! To this day there are absolutely no problems visible at all, but since then I've been very keen to rip the tiles off and check the condition of the plasterboard!
We are now toying with the idea of moving house in a year or two, so it remains to be seen whether we do actually redo the bathroom. If we do, replacing those tiles will be one of the first things I do coz I'm dieing to see the plasterboard behind them!