The AVI container Camstudio currently uses has various limitations in its use that cause Camstudio to crash when video files exceed 2 GB. Matroska should be able to handle the CamStudio lossless codec without the same kind of limitations. This could potentially increase the usefulness of Camstudio, as well as involve open-source containers, making Camstudio more open overall.
I'm not asking for ditching AVI, as AVI is a container that common video editor's recognize easily, while Matroska support is less common. Instead I think for those whose purposes allow Matroska would appreciate that option in addition to AVI support.