I think the title says it all...
As with the increasingly widespread use of ".oga" as a file extension for Ogg/Vorbis audio files (instead of .ogg), I think this extension should be added to the default extension list which in_vorbis.dll claims.
So that this extension would be registered to Winamp by default.
Reason is that the Ogg container can also contain video, and video files are then named .ogv. Many podcasters that provide Ogg support (for Mozilla's browsers, for example) now begin using the .oga extension instead of .ogg for audio-only files.
I can play .oga files fine by adding OGA to the extension list of in_dshow.dll, as I have a Vorbis DirectShow filter.
But then they are played through the generic in_dshow interface, thus missing support for metadata etc. To get the default metadata display, I would have to rename the files to .ogg so they are played by in_vorbis.dll.
The easiest way to fix this would be to add .oga to in_vorbis's list.
Thanks for reading and maybe implementing it in the next version!