I hope I will not be flamed for this question, but I have been out of the loop for the last five years. Therefore my question is: what do you consider the most important changes to LaTeX in the last five years, or asked differently: if you hadn't used LaTeX those past five years, where would you set priorities to relearn it. The aim is to publish scientific papers in Economics with advanced mathematic typesetting and preferably integration of output from R (so sweave is already on my mind).
A small addendum: Which distribution do you prefer? Out of habit I have downloaded MiKTeX, but maybe there is something decisively better out there?