Much in the same way that operating systems currently associate particular file types with specific applications, future Web browsers are likely going to associate semantically marked up data you encounter on the Web with specific applications, either on your system or online.
This is a problem that only the browser can solve. Just like with RSS, it is time for Web browsers to provide the user with a clean, consistent, and simplistic user interface.
Looking only at the user experience level I have to agree with Alex. But what about interoperability between different services?
Micro formats are a great thing but I only see them being used either as a publishing format or by aggregators as a way to identify pieces of information otherwise useless. What if you want to send structured information from one service to another?
Some work needs to be done on the server side as well. Applications must be aware of micro formats and react accordingly.