Being of a Computer Science background I think it useful if not important that developers have some understanding of what’s going on behind the scenes. It can be a real time saver in choosing the right approach in solving a particular problem. In the Flex framework for example, we have full access to the source code via the open source SDK. However for some decisions it is handy to know the low level implementation. The Flash Player tends to be something a black-box with our knowledge constrained to the documentation which largely covers the ‘what’ is available — but only at a high level ever covers the ‘why’ or ‘how’.
To that end it is especially good to see Tinic Uro finding enough time to blog more frequently recently particularly with the changes for Flash Player 10.1. Tinic’s blog is essential reading for any Flash developer. The two most recent posts: