I just started pumping for DD2. I bought new membranes, storage bags, and bottles. Just cleaned everything else. As OP said, medela changed their nipples and rings. My old bottles looked gross so that's why I replaced them.
Mom to two amazing DDs ('07 & '09) and a fur baby.
Gluten free since Nov '11 after non-celiac gluten sensitive diagnosis. Have had great improvement or total elimination of: migraines, bloating/distention, heartburn, cystic acne, canker sores, bleeding gums, eczema on elbows, dry skin and scalp, muscle cramps, PMS, hair loss, heart palpitations, fatigue. I'm amazed.