Technically he's still doing products. I'm sure that he's had different levels of input in all of the YC companies.
The viaweb project was created to exit so they would become dot com millionaires. That's still their continuing mission.
Hackernews is a product. There is no buyer, it is still a product.
Maybe the YC startups are the products? :)
If higher-order functions can produce functions, could there be a higher order companies which produce companies?
The name YCombinator is not accidental. The holy-grail is the fixed-point for startups.