Loic Le Meur's Vision of Programmable Twitter Clients
loiclemeur.com
loiclemeur.com
I see twitter client after twitter client that reproduces the majority of the functionality of its competitors, but each with one unique difference.
It'd be great to not have to always be checking out new clients and deciding if the utility of its unique feature is worth the effort of using another app.
(I'm involved in Seesmic, as both a disclosure but also a "direct to the source" opportunity!).
Of course most of the Internet users today, weren't users in the 90s, so this doesn't mean you wont find users to appreciate what you are offering.
The idea is to allow 3rd party developers to build scripts/plugins/etc that users can download and change their twitter client experience.
Think less Eudora and more Firefox plugins.