A client that connects up, subscribes, and then gets updates as they happen might be an easier start.
Connects via another port?
Or would you teach bitcoin's minimal http implementation to keep the connection open? (and service multiple connections at once)
I've got a use case (google App Engine) where a persistent connection to bitcoin isn't possible (App Engine apps can fetch URLs, and can act as 'web hooks', but can't just open a socket and listen).