While I'm a staunch proponent of building code that reuses other work as much as possible, there comes a time when new ideas, implementations, or just plain better work means either your dependencies are co-dependent (ha) or simply obsolete.
There have been several threads on Drupal's development list as well as the Duplicated modules hall of shame about duplication of functionality in contributed modules.
I wrote http://drupal.org/project/swfobject_api">SWF Object API to address the need to have an API for modules to embed their own flash. At the time, there were no options for doing this. However, in the intervening time, the http://drupal.org/project/swftools">SWF Tools module has started providing a much more comprehensive mechanisms for embedding flash in a variety of ways.
Thanks to some help from joachim , I did some work to create an integration between the Audio module and XSPF Playlist. This means that if you have been using the Audio module to organize and play audio content, you can add in the XSPF Playlist module and the XSPF Audio module to get xspf playlists for your audio files. This is helpful if you are trying to to feed your audio files to a flash player for example.