It's really important to understand that the news aggregation site is not about topic or implementation, it's all about the community around it. So instead of forming your own, why not improve existing? Filtered by "open-source" tag?

By no means trying to ruin your enthusiasm here, but please DO consider using one of the existing aggregators for the same purpose.

Also Open Source seems like a very broad topic to me, covering most of the programming languages, *nix systems and so on...