I hadn't actually looked at the Seymour Duncan website for almost a year - just at my price lists on the computer. They have A LOT of new stuff. How many kinds of pickups do they make now?
The monumental effort it takes to design, test and market a product (pickups, pedals, etc) takes quite a team of people, so a few products a year with worldwide distribution seems about right.
There's probably also some limit to the total number of products SD can handle at a given time. Add too many, and you'd likely have to start discontinuing other models, leading to uproar, riots and violence.