Andrew doesnt really do much of the coding anymore. He hires ppl to do that, and just sits and says what needs to be done. Soon, he would retire and just have other ppl do all the work. Only way it could end is by some time, if graphics advanced to such a degree that it would take jagex too long to translate it's current code into a newer version, then it will end. It took them about a year to do RS1 into RS2 and map was even much smaller then. If they were to do RS3, it may take them 2+, 3+ or even longer due to it's current expansions on maps, NPCs, quests. etc.