Alex Iskold has posted a great review of Dapper over on Read/Write Web. It provides a thorough examination of Dapper and its implications and place on the web.
One thing to note is that Dapper can indeed be used beyond a read-only context – you can easily create a Dapp for a site where you submit content (e.g. sending a message on a social network).
Give the review a read and feel free, as always, to be in touch with your feedback.