I've always read (and been told) that you should empty the pack during your off season (if you have one). You'll need to do regular cleaning and maintenance on your stove - well most stoves. You'll need to at least thoroughly air out your sleeping bag if not actually wash it. It'll will need to be stored loosely. Your pack probably will need at least a good shake out, maybe a spot cleaning, and possibly and real wash. It's also a great opportunity to access each piece of equipment for wear and tear and whether it was literally "worth its weight."