Back in 2001, the MIT announced aspect-oriented programming as a key technology in the next 10 years. Nowadays, 8 years later, AOP is not widely adopted. Several reasons can explain this distrust in front of AOP, and one of them is the lack of robust tools for analysis, testing and maintenance. In order to develop dedicated solutions for assisting the development with AOP, and increase its adoption, we need to understand how it is actually used. In this paper we analyze 38 aspect-oriented open source projects with respect to the impact of aspects on the projects, and to coverage of the language features. This reveals that AOP is currently used in a cautious way. This work is a first step to built support and development tools dedicated to actual practices for AOP, based on empirical usage profiles.