I think at a practical level, opening up their API for non-watered-down third-party clients would be the only true way to add more optionality to twitter's feed

I think at a practical level, opening up their API for non-watered-down third-party clients would be the only true way to add more optionality to twitter's feed UX. Since I don't see open sourcing the actual feed algorithm to be something that would practically happen any time soon (which makes me a sad panda).